C Program to Remove all Characters in a String Except Alphabet

This program takes a strings from user and removes all characters in that string except alphabets.

To understand this example, you should have the knowledge of following C programming topics:

Example: Remove Characters in String Except Alphabets

#include<stdio.h>

int main()
{
    char line[150];
    int i, j;
    printf("Enter a string: ");
    gets(line);

    for(i = 0; line[i] != '\0'; ++i)
    {
        while (!( (line[i] >= 'a' && line[i] <= 'z') || (line[i] >= 'A' && line[i] <= 'Z') || line[i] == '\0') )
        {
            for(j = i; line[j] != '\0'; ++j)
            {
                line[j] = line[j+1];
            }
            line[j] = '\0';
        }
    }
    printf("Output String: ");
    puts(line);
    return 0;
}

Output

Enter a string: p2'r-o@gram84iz./
Output String: programiz

This program takes a string from the user and stored in the variable line.

The, within the for loop, each character in the string is checked if it's an alphabet or not.

If any character inside a string is not a alphabet, all characters after it including the null character is shifted by 1 position to the left.