PHP array_walk() Function (original) (raw)
Last Updated : 20 Jun, 2023
The array_walk() function is an inbuilt function in PHP. The array_walk() function walks through the entire array regardless of pointer position and applies a callback function or user-defined function to every element of the array. The array element's keys and values are parameters in the callback function.Syntax:
boolean array_walk($array, myFunction, $extraParam)
Parameters: This function accepts three parameters as described below:
- $array: This is a mandatory parameter and specifies the input array.
- myFunction: This parameter specifies the name of the user-defined function and is also mandatory. The user-defined function generally excepts two parameters of which the first parameter represent the array's values and the second parameter represents the corresponding keys.
- $extraparam: This is an optional parameter. It specifies an extra parameter to the user-defined function in addition to the two parameters, array keys and values.
Return value: This function returns a boolean value. It returns TRUE on success or FALSE on failure. Below programs illustrate the array_walk() function:Program 1:
PHP `
keyhasthevaluekey has the value keyhasthevaluevalue \n"; } // Input array $arr = array("a"=>"yellow", "b"=>"pink", "c"=>"purple"); // calling array_walk() with no extra parameter array_walk($arr, "myfunction"); ?>`
Output:
The key a has the value yellow The key b has the value pink The key c has the value purple
Program 2:
PHP `
key,key, key,extraParam) { echo "The key keykey keyextraParam $value \n"; } // Input array $arr = array("a"=>"yellow", "b"=>"pink", "c"=>"purple"); // calling array_walk() with extra parameter array_walk($arr, "myfunction", "has the value"); ?>`
Output:
The key a has the value yellow The key b has the value pink The key c has the value purple
Program 3:
php `
value=value = value=value + 10; } // Input array $arr = array("first"=>10, "second"=>20, "third"=>30); // calling array_walk() with no extra parameter array_walk($arr, "myfunction"); // printing array after updating values print_r($arr); ?>`
Output:
Array ( [first] => 20 [second] => 30 [third] => 40 )