C++ program to remove all character from string except alphabets

October 13, 2022

Removing all characters from the string except alphabets.

In this article we will be learning about Removing all characters from the string except alphabets.

Removing all characters excepts alphabets means removing special characters like ‘*’, ‘?’,  ‘@’,  etc. and numeric characters like ‘1’, ‘2’, ‘3’, etc. from the input string.

input string :- 1_pre9pins34a

Output sting:- prepinsta

Removing all characters from the string except alphabets

Algorithm:

  • Initialize the variables.
  • Accept the input.
  • Initialize a for loop and terminate it at the end of string.
  • Iterate each character through the loop.
  • Remove non alphabetical characters using while loop.
  • Store only alphabetical characters from the string using another for loop
  • Print result.
While loop in C

C++ programming code to remove all characters from string except alphabets

Run 
#include <iostream>
using namespace std;
int main()
{
    //Initializing variable.
    char str[100];
    int i, j;
    
    //Accepting input.
    cout<<"Enter a string : ";
    gets(str);

    //Iterating each character and removing non alphabetical characters.
    for(i = 0; str[i] != '\0'; ++i)
    {
        while (!( (str[i] >= 'a' && str[i] <= 'z') || (str[i] >= 'A' && str[i] <= 'Z') || str[i] == '\0') )
        {
            for(j = i; str[j] != '\0'; ++j)
            {
                str[j] = str[j+1];
            }
            str[j] = '\0'; 
        }
    }
    //Printing output.
    cout<<"After removing non alphabetical characters the string is :";
    puts(str);
    return 0;
}
Output:
Enter a string : *1prep_insta*
After removing non alphabetical characters the string is :prepinsta

Method 2

Run 
#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 = "P*re;p..ins't^a?";
    removeSpecialCharacter(s);
    return 0;
}

Output

Prepinsta
 
 

Toggle each character in a string

Find the ASCII value of a character

Length of the string without using strlen() function

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While loop in C

6 comments on “C++ program to remove all character from string except alphabets”


  • akshay

    #include
    using namespace std;

    int main(int argc, char const *argv[])
    {
    string str=”P*re;p..ins’t^a?”;
    int n=str.length();
    string res=””;

    for(int i=0; i<n; i++){
    if(isdigit(str[i]))
    continue;
    if(isalpha(str[i]))
    res+=str[i];
    else
    continue;
    }

    cout<<res;
    return 0;
    }


  • vishal

    #include
    #include
    using namespace std;
    int main(){
    string str;
    cout<<"enter a string"<= ‘a’ && str[i] = ‘A’ && str[i] <= 'Z'))
    {
    cout<<str[i];
    }
    }
    return 0;

    }


  • Pooja

    //another simple solution
    #include
    #include

    using namespace std;

    int main ()
    {

    char ch[100];
    cin>>ch;
    int count=0;
    int len=strlen(ch);
    for(int i=0; i=’A’&& ch[i]=’a’&& ch[i]<='z'))
    {
    continue;
    }
    else
    {
    for(int j=i; j<len; j++)
    {
    ch[j]=ch[j+1];
    }

    len–;
    i–;

    }
    }
    cout<<ch;

    }


  • Promit

    #include
    #include
    using namespace std;
    int main()
    {
    char a[100],b[100];
    int i=0,j=0,k=-1;
    gets(a);
    for(i=0;a[i]!=’\0′;i++)
    {

    if(a[i]>=’a’&&a[i]=’A’&&a[i]<='Z')
    {
    k++;
    a[k]=a[i];

    }
    else
    {
    continue;
    }
    }
    a[k+1]='\0';
    puts(a);

    }