Remove all Characters in a String Except Alphabet

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

Source Code to 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 user and for loop executed until all characters of string is checked. If any character inside a string is not a alphabet, all characters after it including null character is shifted by 1 position backwards.