Remove all characters other than alphabets from string (original) (raw)

Given a string consisting of alphabets and others characters, remove all the characters other than alphabets and print the string so formed.

**Examples:

**Input : $Gee*k;s..fo, r'Ge^eks?
**Output : GeeksforGeeks

**Input : P&ra+$BHa;;t*ku, ma$r@@s#in}gh
**Output : PraBHatkumarsingh

To remove all the characters other than alphabets(a-z) && (A-Z), we just compare the character with the ASCII value, and for the character whose value does not lie in the range of alphabets, we remove those characters using string erase function.

**Implementation:

C++ `

// CPP program to remove all the // characters other than alphabets #include <bits/stdc++.h> using namespace std;

// function to remove characters and // print new string void removeSpecialCharacter(string s) { for (int i = 0; i < s.size(); i++) {

    // Finding the character whose
    // ASCII value fall under this
    // range
    if (s[i] < 'A' || s[i] > 'Z' && s[i] < 'a'
        || s[i] > 'z') {
        // erase function to erase
        // the character
        s.erase(i, 1);
        i--;
    }
}
cout << s;

}

// driver code int main() { string s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s); return 0; }

Java

// Java program to remove all the characters // other than alphabets

class GFG {

// function to remove characters and
// print new string
static void removeSpecialCharacter(String s)
{
    for (int i = 0; i < s.length(); i++)
    {

        // Finding the character whose 
        // ASCII value fall under this
        // range
        if (s.charAt(i) < 'A' || s.charAt(i) > 'Z' &&
                s.charAt(i) < 'a' || s.charAt(i) > 'z') 
        { 
            
            // erase function to erase 
            // the character
            s = s.substring(0, i) + s.substring(i + 1);
            i--;
        }
    }
    System.out.print(s);
}

// Driver code
public static void main(String[] args)
{
    String s = "$Gee*k;s..fo, r'Ge^eks?"; 
    removeSpecialCharacter(s);
} 

}

// This code is contributed by Rajput-Ji

Python3

Python3 program to remove all the

characters other than alphabets

function to remove characters and

print new string

def removeSpecialCharacter(s):

i = 0

while i < len(s):

    # Finding the character whose
    # ASCII value fall under this
    # range
    if (ord(s[i]) < ord('A') or 
        ord(s[i]) > ord('Z') and 
        ord(s[i]) < ord('a') or 
        ord(s[i]) > ord('z')):
            
        # erase function to erase
        # the character
        del s[i]
        i -= 1
    i += 1

print("".join(s))

Driver Code

if name == 'main': s = "$Gee*k;s..fo, r'Ge^eks?" s = [i for i in s] removeSpecialCharacter(s)

This code is contributed by Mohit Kumar

C#

// C# program to remove all the characters // other than alphabets using System;

class GFG {

// function to remove characters and
// print new string
static void removeSpecialCharacter(string s)
{
    for (int i = 0; i < s.Length; i++)
    {

        // Finding the character whose 
        // ASCII value fall under this
        // range
        if (s[i] < 'A' || s[i] > 'Z' &&
                s[i] < 'a' || s[i] > 'z') 
        { 
            
            // erase function to erase 
            // the character
            s = s.Remove(i,1);
            i--;
        }
    }
    
    Console.Write(s);
}

// Driver code
public static void Main()
{
    string s = "$Gee*k;s..fo, r'Ge^eks?"; 
    removeSpecialCharacter(s);
} 

}

// This code is contributed by Sam007.

JavaScript

`

**Time complexity: O(N 2 ) as erase() may take O(n) in the worst case. We can optimize the solution by keeping track of two indexes.
**Auxiliary Space: O(1)

**Implementation:

C++ `

// CPP program to remove all the // characters other than alphabets #include <bits/stdc++.h> using namespace std;

// function to remove characters and // print new string void removeSpecialCharacter(string s) { int j = 0; for (int i = 0; i < s.size(); i++) {

    // Store only valid characters
    if ((s[i] >= 'A' && s[i] <= 'Z') ||
        (s[i] >='a' && s[i] <= 'z'))
    { 
        s[j] = s[i];
        j++;
    }
}
cout << s.substr(0, j);

}

// driver code int main() { string s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s); return 0; }

Java

// Java program to remove all the // characters other than alphabets

class GFG {

// function to remove characters and // print new string static void removeSpecialCharacter(String str) { char[] s = str.toCharArray(); int j = 0; for (int i = 0; i < s.length; i++) {

        // Store only valid characters 
        if ((s[i] >= 'A' && s[i] <= 'Z')
                || (s[i] >= 'a' && s[i] <= 'z')) {
            s[j] = s[i];
            j++;
        }
    }
    System.out.println(String.valueOf(s).substring(0, j));
}

// driver code public static void main(String[] args) { String s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s); } }

// This code is contributed by 29AjayKumar

Python3

Python program to remove all the

characters other than alphabets

Function to remove special characters

and store it in another variable

def removeSpecialCharacter(s): t = "" for i in s:

    # Store only valid characters
    if (i >= 'A' and i <= 'Z') or (i >= 'a' and i <= 'z'):
        t += i
print(t)

Driver code

s = "$Gee*k;s..fo, r'Ge^eks?" removeSpecialCharacter(s)

This code is contributed by code_freak

C#

// C# program to remove all the // characters other than alphabets using System; public class GFG {

// function to remove characters and // print new string static void removeSpecialCharacter(String str) { char[] s = str.ToCharArray(); int j = 0; for (int i = 0; i < s.Length; i++) {

        // Store only valid characters 
        if ((s[i] >= 'A' && s[i] <= 'Z')
                || (s[i] >= 'a' && s[i] <= 'z')) {
            s[j] = s[i];
            j++;
        }
    }
    Console.WriteLine(String.Join("",s).Substring(0, j));
}

// driver code public static void Main() { String s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s); } } //This code is contributed by PrinciRaj1992

JavaScript

`

**Time Complexity: **O(n)
**Auxiliary Space: O(1)

**Approach : Using isalpha() method:

Iterate over the characters of the string and if the character is an alphabet then add the character to the new string. Finally, the new string contains only the alphabets of the given string.

**Implementation:

C++ `

// CPP program to remove all the // characters other than alphabets #include <bits/stdc++.h> using namespace std;

// function to remove characters and // print new string void removeSpecialCharacter(string s) { // Initialize an empty string string ans = ""; for (auto ch : s) { // if the current character // is an alphabet if (isalpha(ch)) ans += ch; } cout << ans; }

// driver code int main() { string s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s); return 0; }

// this code is contributed by Rajdeep Mallick(rajdeep999)

Java

public class Main { // function to remove characters and print new string static void removeSpecialCharacter(String s) { // Initialize an empty string String ans = ""; for (char ch : s.toCharArray()) { // if the current character is an alphabet if (Character.isLetter(ch)) ans += ch; } System.out.println(ans); }

// driver code
public static void main(String[] args) {
    String s = "$Gee*k;s..fo, r'Ge^eks?";
    removeSpecialCharacter(s);
}

}

Python3

Python program to remove all the

characters other than alphabets

Function to remove special characters

and store it in another variable

def removeSpecialCharacter(s): t = "" for i in s: if(i.isalpha()): t+=i print(t) s = "$Gee*k;s..fo, r'Ge^eks?" removeSpecialCharacter(s)

C#

using System;

public class Program { public static void Main() { string s = "$Gee*k;s..fo, r'Ge^eks?"; RemoveSpecialCharacter(s); }

// function to remove characters and print new string
public static void RemoveSpecialCharacter(string s)
{
    // Initialize an empty string
    string ans = "";
    foreach(char ch in s)
    {
        // if the current character is an alphabet
        if (Char.IsLetter(ch))
            ans += ch;
    }
    Console.WriteLine(ans);
}

}

// This code is contributed by sarojmcy2e

JavaScript

// function to remove characters and print new string function removeSpecialCharacter(s) { // Initialize an empty string let ans = ""; for (let i = 0; i < s.length; i++) { // if the current character is an alphabet if (/[a-zA-Z]/.test(s[i])) { ans += s[i]; } } console.log(ans); }

// driver code let s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s);

// This code is contributed by princekumaras

`

**Time Complexity: O(n)
**Auxiliary Space: O(n)

**Approach: Without built-in methods.

Initialize an empty string, string with lowercase alphabets(_la) and uppercase alphabets(_ua). Iterate a for loop on string, if the character is in _la or ua using **in and not in operators concatenate them to an empty string. Display the string after the end of the loop.

**Implementation:

C++ `

// C++ program to remove all the // characters other than alphabets #include<bits/stdc++.h> using namespace std; string removeSpecialCharacter(string s) { string t = ""; string la = "abcdefghijklmnopqrstuvwxyz"; string ua = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; for (int i = 0; i < s.length(); i++) { if(la.find(s[i]) != string::npos || ua.find(s[i]) != string::npos) { t += s[i]; } } cout << t << endl; return t; } int main() { string s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s); return 0; }

// This code is contributed by shivamsharma215

Java

// Java program to remove all the // characters other than alphabets import java.util.*;

class Gfg { static String removeSpecialCharacter(String s) { // empty string to store the result String t = ""; String la = "abcdefghijklmnopqrstuvwxyz"; String ua = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; for (int i = 0; i < s.length(); i++) {

      // if it is a letter, add it to the result string
        if (la.contains(String.valueOf(s.charAt(i)))
            || ua.contains(
                String.valueOf(s.charAt(i)))) {
            t += s.charAt(i);
        }
    }
    System.out.println(t);
    return t;
}

// Driver Code
public static void main(String[] args)
{
    String s = "$Gee*k;s..fo, r'Ge^eks?";
    removeSpecialCharacter(s);
}

}

Python3

Python program to remove all the

characters other than alphabets

Function to remove special characters

and store it in another variable

def removeSpecialCharacter(s): t = "" la="abcdefghijklmnopqrstuvwxyz" ua="ABCDEFGHIJKLMNOPQRSTUVWXYZ" for i in s: if(i in la or i in ua): t+=i print(t) s = "$Gee*k;s..fo, r'Ge^eks?" removeSpecialCharacter(s)

C#

// C# program to remove all the // characters other than alphabets using System;

class Gfg{ static string removeSpecialCharacter(string s) { string t = ""; string la = "abcdefghijklmnopqrstuvwxyz"; string ua = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; for (int i = 0; i < s.Length; i++) if(la.Contains(s[i]) || ua.Contains(s[i])) t += s[i];

    Console.WriteLine(t);
    return t;
}
public static void Main() 
{
  string s = "$Gee*k;s..fo, r'Ge^eks?";
  removeSpecialCharacter(s);
}

}

JavaScript

// JS program to remove all the // characters other than alphabets function removeSpecialCharacter( s) { let t = ""; let la = "abcdefghijklmnopqrstuvwxyz"; let ua = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; for (let i = 0; i < s.length; i++) { if(la.includes(s[i]) || ua.includes(s[i])) { t += s[i]; } } console.log(t); return t; } let s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s);

// this code is contributed by poojaagarwal2.

`

**Time complexity: O(n), where n is the length of the input string s. This is because in the worst case, the loop in the removeSpecialCharacter function will have to iterate through all the characters in the string.
**Auxiliary Space: O(n), where n is the length of the final string without special characters. This is because the function creates a new string t to store only the alphabetic characters. The size of the string t will be at most equal to the size of the original string s.

**Approach: Using **ord() function.The ASCII value of the lowercase alphabet is from 97 to 122. And, the ASCII value of the uppercase alphabet is from 65 to 90.

C++ `

#include <bits/stdc++.h> using namespace std;

// Function to remove special characters // and store it in another variable void removeSpecialCharacter(string s) { string t = ""; for (int i = 0; i < s.length(); i++) { if ((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z')) { t += s[i]; } } cout << t << endl; }

int main() { string s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s); return 0; }

Java

import java.util.*;

class GFG { // Function to remove special characters // and store it in another variable static void removeSpecialCharacter(String s) { String t = ""; for (int i = 0; i < s.length(); i++) { if ((s.charAt(i) >= 'a' && s.charAt(i) <= 'z') || (s.charAt(i) >= 'A' && s.charAt(i) <= 'Z')) { t += s.charAt(i); } } System.out.println(t); }

public static void main(String[] args) {
    String s = "$Gee*k;s..fo, r'Ge^eks?";
    removeSpecialCharacter(s);
}

}

Python3

Python program to remove all the

characters other than alphabets

Function to remove special characters

and store it in another variable

def removeSpecialCharacter(s): t = "" for i in s: if(ord(i) in range(97,123) or ord(i) in range(65,91)): t+=i print(t) s = "$Gee*k;s..fo, r'Ge^eks?" removeSpecialCharacter(s)

C#

using System;

class GFG { // Function to remove special characters // and store it in another variable static void RemoveSpecialCharacter(string s) { string t = ""; for (int i = 0; i < s.Length; i++) { // Check if the character is an alphabet // (lowercase or uppercase) if ((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z')) { t += s[i]; } } Console.WriteLine(t); }

static void Main(string[] args)
{
    string s = "$Gee*k;s..fo, r'Ge^eks?";
    RemoveSpecialCharacter(s);
}

}

JavaScript

// JavaScript program to remove all the // characters other than alphabets

// Function to remove special characters // and store it in another variable function removeSpecialCharacter(s) { let t = "" for (let i=0; i<s.length; i++) if((s[i]>='a' && s[i]<='z') || (s[i]>='A' && s[i]<='Z')) t+=s[i]; console.log(t); } let s = "$Gee*k;s..fo, r'Ge^eks?"; removeSpecialCharacter(s);

`