Function for Removing Forbidden Characters in C++

Discuss the way to remove functions that will remove forbidden characters like [ ‘ : ’, ‘ ? ‘, ‘ \ ’, ‘ / ’, ‘ < ’, ‘ > ’, ‘ | ’, ‘ * ’ ] from a string, for example

Input: str = “ Hello: Welco*me/ to Tu>torials point|. ”
Output: “ Hello Welcome to Tutorials point. ”
Explanation: Input String contains forbidden characters which got removed and new string has no forbidden characters.

Input: str = “ How/ are y*ou doi,ng? ”
Output: “ How are you doing ”

Approach to Find the Solution

A simple approach that can be applied to this problem is,

• Traverse the string from any side.

• Check for each character if it belongs to forbidden characters.

• Remove the character if it belongs to forbidden characters.

• We can either insert a null value or a new string to insert all the characters except forbidden in removing characters.

Example

C++ Code for the Above Approach

#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
// function to remove forbidden charcters.
void removeforbidden(char* str){
    int j = 0;
    int n =  strlen(str);
    // traversing through the string and searching for forbidden characters.
    for(int i = 0;i<n;i++){
        switch(str[i]){
            case '/':
            case '\':
            case ':':
            case '?':
            case '"':
            case '<':
            case '>':
            case '|':
            case '*':
            // inserting null value in place of forbidden characters.
            str[j] = '\0';
            default:
            str[j++] = str[i];

        }
    }  
    // printing the string.
    for(int i = 0;i<n;i++)
        cout << str[i];
    return;
}
int main(){
    char str[] = "Hello: Welco*me/ to Tu>torial?s point|.";
    removeforbidden(str);
    return 0;
}

Output

Hello, Welcome to Tutorials point.

Explanation of the Above Code

• Switch case is used while traversing through the string in which each element of a string is checked with the case characters.

• If a character equals the case character, then it is replaced by a null character.

Conclusion

In this tutorial, we discussed created a Function for removing forbidden characters like [ ‘ : ’, ‘ ? ‘, ‘ \ ’, ‘ / ’, ‘ < ’, ‘ > ’, ‘ | ’, ‘ * ’ ] We discussed a simple approach to solve this problem by traversing through the string and matching the characters with forbidden characters.

We also discussed the C++ program for this problem which we can do with programming languages like C, Java, Python, etc. We hope you find this tutorial helpful.