PHP: base_convert - Manual (original) (raw)

(PHP 4, PHP 5, PHP 7, PHP 8)

base_convert — Convert a number between arbitrary bases

Description

Warning

base_convert() may lose precision on large numbers due to properties related to the internal float type used. Please see the Floating point numbers section in the manual for more specific information and limitations.

Parameters

num

The number to convert. Any invalid characters innum are silently ignored. As of PHP 7.4.0 supplying any invalid characters is deprecated.

from_base

The base num is in

to_base

The base to convert num to

Return Values

num converted to base to_base

Changelog

Version Description
7.4.0 Passing invalid characters will now generate a deprecation notice. The result will still be computed as if the invalid characters did not exist.

Examples

Example #1 base_convert() example

<?php
$hexadecimal = 'a37334';
echo base_convert($hexadecimal, 16, 2);
?>

The above example will output:

See Also

Found A Problem?

PHPCoder at niconet2k dot com

14 years ago

Convert an arbitrarily large number from any base to any base.

string convBase(string <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi><mi>b</mi><mi>e</mi><mi>r</mi><mi>I</mi><mi>n</mi><mi>p</mi><mi>u</mi><mi>t</mi><mo separator="true">,</mo><mi>s</mi><mi>t</mi><mi>r</mi><mi>i</mi><mi>n</mi><mi>g</mi></mrow><annotation encoding="application/x-tex">numberInput, string </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">mb</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mord mathnormal" style="margin-right:0.07847em;">I</span><span class="mord mathnormal">n</span><span class="mord mathnormal">p</span><span class="mord mathnormal">u</span><span class="mord mathnormal">t</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mord mathnormal">in</span><span class="mord mathnormal" style="margin-right:0.03588em;">g</span></span></span></span>fromBaseInput, string $toBaseInput)
$numberInput number to convert as a string
$fromBaseInput base of the number to convert as a string
$toBaseInput base the number should be converted to as a string
examples for <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mi>r</mi><mi>o</mi><mi>m</mi><mi>B</mi><mi>a</mi><mi>s</mi><mi>e</mi><mi>I</mi><mi>n</mi><mi>p</mi><mi>u</mi><mi>t</mi><mi>a</mi><mi>n</mi><mi>d</mi></mrow><annotation encoding="application/x-tex">fromBaseInput and </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord mathnormal">ro</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mord mathnormal">a</span><span class="mord mathnormal">se</span><span class="mord mathnormal" style="margin-right:0.07847em;">I</span><span class="mord mathnormal">n</span><span class="mord mathnormal">p</span><span class="mord mathnormal">u</span><span class="mord mathnormal">t</span><span class="mord mathnormal">an</span><span class="mord mathnormal">d</span></span></span></span>toBaseInput
'0123456789ABCDEF' for Hexadecimal (Base16)
'0123456789' for Decimal (Base10)
'01234567' for Octal (Base8)
'01' for Binary (Base2) 
You can really put in whatever you want and the first character is the 0.
Examples:

<?php 
convBase('123', '0123456789', '01234567'); 
//Convert '123' from decimal (base10) to octal (base8).
//result: 173

convBase('70B1D707EAC2EDF4C6389F440C7294B51FFF57BB', '0123456789ABCDEF', '01');
//Convert '70B1D707EAC2EDF4C6389F440C7294B51FFF57BB' from hexadecimal (base16) to binary (base2).
//result: 
//111000010110001110101110000011111101010110000101110
//110111110100110001100011100010011111010001000000110
//001110010100101001011010100011111111111110101011110
//111011

convBase('1324523453243154324542341524315432113200203012', '012345', '0123456789ABCDEF');
//Convert '1324523453243154324542341524315432113200203012' from senary (base6) to hexadecimal (base16).
//result: 1F9881BAD10454A8C23A838EF00F50

convBase('355927353784509896715106760','0123456789','Christopher');
//Convert '355927353784509896715106760' from decimal (base10) to undecimal (base11) using "Christopher" as the numbers.
//result: iihtspiphoeCrCeshhorsrrtrh

convBase('1C238Ab97132aAC84B72','0123456789aAbBcCdD', '~!@#$%^&*()');
//Convert'1C238Ab97132aAC84B72' from octodecimal (base18) using '0123456789aAbBcCdD' as the numbers to undecimal (base11) using '~!@#$%^&*()' as the numbers.
//result: !%~!!*&!~^!!&(&!~^@#@@@&

function convBase($numberInput, <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mi>r</mi><mi>o</mi><mi>m</mi><mi>B</mi><mi>a</mi><mi>s</mi><mi>e</mi><mi>I</mi><mi>n</mi><mi>p</mi><mi>u</mi><mi>t</mi><mo separator="true">,</mo></mrow><annotation encoding="application/x-tex">fromBaseInput, </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord mathnormal">ro</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mord mathnormal">a</span><span class="mord mathnormal">se</span><span class="mord mathnormal" style="margin-right:0.07847em;">I</span><span class="mord mathnormal">n</span><span class="mord mathnormal">p</span><span class="mord mathnormal">u</span><span class="mord mathnormal">t</span><span class="mpunct">,</span></span></span></span>toBaseInput)
{
    if ($fromBaseInput==$toBaseInput) return $numberInput;
    <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mi>r</mi><mi>o</mi><mi>m</mi><mi>B</mi><mi>a</mi><mi>s</mi><mi>e</mi><mo>=</mo><mi>s</mi><mi>t</mi><msub><mi>r</mi><mi>s</mi></msub><mi>p</mi><mi>l</mi><mi>i</mi><mi>t</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">fromBase = str_split(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord mathnormal">ro</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mord mathnormal">a</span><span class="mord mathnormal">se</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">s</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal" style="margin-right:0.01968em;">pl</span><span class="mord mathnormal">i</span><span class="mord mathnormal">t</span><span class="mopen">(</span></span></span></span>fromBaseInput,1);
    <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>t</mi><mi>o</mi><mi>B</mi><mi>a</mi><mi>s</mi><mi>e</mi><mo>=</mo><mi>s</mi><mi>t</mi><msub><mi>r</mi><mi>s</mi></msub><mi>p</mi><mi>l</mi><mi>i</mi><mi>t</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">toBase = str_split(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal">t</span><span class="mord mathnormal">o</span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mord mathnormal">a</span><span class="mord mathnormal">se</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">s</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal" style="margin-right:0.01968em;">pl</span><span class="mord mathnormal">i</span><span class="mord mathnormal">t</span><span class="mopen">(</span></span></span></span>toBaseInput,1);
    <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi><mi>b</mi><mi>e</mi><mi>r</mi><mo>=</mo><mi>s</mi><mi>t</mi><msub><mi>r</mi><mi>s</mi></msub><mi>p</mi><mi>l</mi><mi>i</mi><mi>t</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">number = str_split(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">mb</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">s</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal" style="margin-right:0.01968em;">pl</span><span class="mord mathnormal">i</span><span class="mord mathnormal">t</span><span class="mopen">(</span></span></span></span>numberInput,1);
    <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mi>r</mi><mi>o</mi><mi>m</mi><mi>L</mi><mi>e</mi><mi>n</mi><mo>=</mo><mi>s</mi><mi>t</mi><mi>r</mi><mi>l</mi><mi>e</mi><mi>n</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">fromLen=strlen(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord mathnormal">ro</span><span class="mord mathnormal">m</span><span class="mord mathnormal">L</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mopen">(</span></span></span></span>fromBaseInput);
    <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>t</mi><mi>o</mi><mi>L</mi><mi>e</mi><mi>n</mi><mo>=</mo><mi>s</mi><mi>t</mi><mi>r</mi><mi>l</mi><mi>e</mi><mi>n</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">toLen=strlen(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6833em;"></span><span class="mord mathnormal">t</span><span class="mord mathnormal">o</span><span class="mord mathnormal">L</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mopen">(</span></span></span></span>toBaseInput);
    <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi><mi>b</mi><mi>e</mi><mi>r</mi><mi>L</mi><mi>e</mi><mi>n</mi><mo>=</mo><mi>s</mi><mi>t</mi><mi>r</mi><mi>l</mi><mi>e</mi><mi>n</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">numberLen=strlen(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">mb</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mord mathnormal">L</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mopen">(</span></span></span></span>numberInput);
    $retval='';
    if ($toBaseInput == '0123456789')
    {
        $retval=0;
        for ($i = 1;$i <= <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi><mi>b</mi><mi>e</mi><mi>r</mi><mi>L</mi><mi>e</mi><mi>n</mi><mo separator="true">;</mo></mrow><annotation encoding="application/x-tex">numberLen; </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">mb</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mord mathnormal">L</span><span class="mord mathnormal">e</span><span class="mord mathnormal">n</span><span class="mpunct">;</span></span></span></span>i++)
            <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>r</mi><mi>e</mi><mi>t</mi><mi>v</mi><mi>a</mi><mi>l</mi><mo>=</mo><mi>b</mi><mi>c</mi><mi>a</mi><mi>d</mi><mi>d</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">retval = bcadd(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">re</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="mord mathnormal">a</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">b</span><span class="mord mathnormal">c</span><span class="mord mathnormal">a</span><span class="mord mathnormal">dd</span><span class="mopen">(</span></span></span></span>retval, bcmul(array_search($number[$i-1], <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>f</mi><mi>r</mi><mi>o</mi><mi>m</mi><mi>B</mi><mi>a</mi><mi>s</mi><mi>e</mi><mo stretchy="false">)</mo><mo separator="true">,</mo><mi>b</mi><mi>c</mi><mi>p</mi><mi>o</mi><mi>w</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">fromBase),bcpow(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mord mathnormal">ro</span><span class="mord mathnormal">m</span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mord mathnormal">a</span><span class="mord mathnormal">se</span><span class="mclose">)</span><span class="mpunct">,</span><span class="mspace" style="margin-right:0.1667em;"></span><span class="mord mathnormal">b</span><span class="mord mathnormal">c</span><span class="mord mathnormal">p</span><span class="mord mathnormal">o</span><span class="mord mathnormal" style="margin-right:0.02691em;">w</span><span class="mopen">(</span></span></span></span>fromLen,$numberLen-$i)));
        return $retval;
    }
    if ($fromBaseInput != '0123456789')
        <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>b</mi><mi>a</mi><mi>s</mi><mi>e</mi><mn>10</mn><mo>=</mo><mi>c</mi><mi>o</mi><mi>n</mi><mi>v</mi><mi>B</mi><mi>a</mi><mi>s</mi><mi>e</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">base10=convBase(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">ba</span><span class="mord mathnormal">se</span><span class="mord">10</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">co</span><span class="mord mathnormal">n</span><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mord mathnormal">a</span><span class="mord mathnormal">se</span><span class="mopen">(</span></span></span></span>numberInput, $fromBaseInput, '0123456789');
    else
        <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>b</mi><mi>a</mi><mi>s</mi><mi>e</mi><mn>10</mn><mo>=</mo></mrow><annotation encoding="application/x-tex">base10 = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">ba</span><span class="mord mathnormal">se</span><span class="mord">10</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>numberInput;
    if ($base10<strlen($toBaseInput))
        return <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>t</mi><mi>o</mi><mi>B</mi><mi>a</mi><mi>s</mi><mi>e</mi><mo stretchy="false">[</mo></mrow><annotation encoding="application/x-tex">toBase[</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">t</span><span class="mord mathnormal">o</span><span class="mord mathnormal" style="margin-right:0.05017em;">B</span><span class="mord mathnormal">a</span><span class="mord mathnormal">se</span><span class="mopen">[</span></span></span></span>base10];
    while($base10 != '0')
    {
        <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>r</mi><mi>e</mi><mi>t</mi><mi>v</mi><mi>a</mi><mi>l</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">retval = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">re</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="mord mathnormal">a</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>toBase[bcmod($base10,$toLen)].$retval;
        <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>b</mi><mi>a</mi><mi>s</mi><mi>e</mi><mn>10</mn><mo>=</mo><mi>b</mi><mi>c</mi><mi>d</mi><mi>i</mi><mi>v</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">base10 = bcdiv(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">ba</span><span class="mord mathnormal">se</span><span class="mord">10</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">b</span><span class="mord mathnormal">c</span><span class="mord mathnormal">d</span><span class="mord mathnormal">i</span><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="mopen">(</span></span></span></span>base10,$toLen,0);
    }
    return $retval;
}
?>

Anonymous

7 years ago

While not immediately clear from the description above, a negative sign is also "silently ignored".

base_convert("-12", 10, 10)   =>   12

lindsay at bitleap dot com

21 years ago

If you need to use base_convert with numbers larger then 32 bit, the following gmp implementation of base_convert should work.

<?php

/*use gmp library to convert base. gmp will convert numbers > 32bit*/
function gmp_convert($num, <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>b</mi><mi>a</mi><mi>s</mi><msub><mi>e</mi><mi>a</mi></msub><mo separator="true">,</mo></mrow><annotation encoding="application/x-tex">base_a, </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">ba</span><span class="mord mathnormal">s</span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mpunct">,</span></span></span></span>base_b)
{
        return gmp_strval ( gmp_init($num, <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>b</mi><mi>a</mi><mi>s</mi><msub><mi>e</mi><mi>a</mi></msub><mo stretchy="false">)</mo><mo separator="true">,</mo></mrow><annotation encoding="application/x-tex">base_a), </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">ba</span><span class="mord mathnormal">s</span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">a</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mclose">)</span><span class="mpunct">,</span></span></span></span>base_b );
}

?>

ardavies at tiscali dot co dot uk

12 years ago

In order to convert base 26 (hexavigesimal) of just alphanumeric characters (A-Z), wthout integers, (as descibed at http://en.wikipedia.org/wiki/Hexavigesimal), I found this to be useful:

function base_convert_alpha(  <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>s</mi><mi>t</mi><mi>r</mi><mo separator="true">,</mo></mrow><annotation encoding="application/x-tex">str,  </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8095em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mpunct">,</span></span></span></span>from,  $to  )
{
    $r = range( 'A', 'Z' );
    <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>c</mi><mi>l</mi><mi>e</mi><mi>a</mi><mi>n</mi><mo>=</mo><mi>s</mi><mi>t</mi><msub><mi>r</mi><mi>r</mi></msub><mi>e</mi><mi>p</mi><mi>l</mi><mi>a</mi><mi>c</mi><mi>e</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">clean = str_replace( </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">c</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">e</span><span class="mord mathnormal">an</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord"><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:-0.0278em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style="margin-right:0.02778em;">r</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal">e</span><span class="mord mathnormal" style="margin-right:0.01968em;">pl</span><span class="mord mathnormal">a</span><span class="mord mathnormal">ce</span><span class="mopen">(</span></span></span></span>r, array_keys($r), $str );
    return base_convert( <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>c</mi><mi>l</mi><mi>e</mi><mi>a</mi><mi>n</mi><mo separator="true">,</mo></mrow><annotation encoding="application/x-tex">clean, </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">c</span><span class="mord mathnormal" style="margin-right:0.01968em;">l</span><span class="mord mathnormal">e</span><span class="mord mathnormal">an</span><span class="mpunct">,</span></span></span></span>from, $to );
}

echo base_convert_alpha(  "BAC",  26,  10  );

//$clean = 102 which then returns 678

ohcc at 163 dot com

8 years ago

<?php
    $v = base_convert(3.14, 10, 10);
    var_dump($v);
?>

output: string(3) "314"

cyrilbele at yahoo dot fr

17 years ago

If you want to do sharding, at some point you will need to decide which shard to target. Here is a simple function to assign the data to a particular shard based on a key (usually identifier of the row)

Here is a simple function to get the shard based on the key and the number of shards available

<?php
function getShard($key,$nbShards) {
    <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi><mo>=</mo><mi>s</mi><mi>u</mi><mi>b</mi><mi>s</mi><mi>t</mi><mi>r</mi><mo stretchy="false">(</mo><mi>b</mi><mi>a</mi><mi>s</mi><msub><mi>e</mi><mi>c</mi></msub><mi>o</mi><mi>n</mi><mi>v</mi><mi>e</mi><mi>r</mi><mi>t</mi><mo stretchy="false">(</mo><mi>s</mi><mi>h</mi><mi>a</mi><mn>1</mn><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">num = substr(base_convert(sha1(</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">m</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">u</span><span class="mord mathnormal">b</span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord mathnormal" style="margin-right:0.02778em;">r</span><span class="mopen">(</span><span class="mord mathnormal">ba</span><span class="mord mathnormal">s</span><span class="mord"><span class="mord mathnormal">e</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist" style="height:0.1514em;"><span style="top:-2.55em;margin-left:0em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">c</span></span></span></span><span class="vlist-s">​</span></span><span class="vlist-r"><span class="vlist" style="height:0.15em;"><span></span></span></span></span></span></span><span class="mord mathnormal">o</span><span class="mord mathnormal">n</span><span class="mord mathnormal" style="margin-right:0.03588em;">v</span><span class="mord mathnormal" style="margin-right:0.02778em;">er</span><span class="mord mathnormal">t</span><span class="mopen">(</span><span class="mord mathnormal">s</span><span class="mord mathnormal">ha</span><span class="mord">1</span><span class="mopen">(</span></span></span></span>key), 16, 10),4,6);
    return <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>n</mi><mi>u</mi><mi>m</mi></mrow><annotation encoding="application/x-tex">num%</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.4306em;"></span><span class="mord mathnormal">n</span><span class="mord mathnormal">u</span><span class="mord mathnormal">m</span></span></span></span>nbShards;
}
?>