Check for Binary String

Last Updated : 23 Nov, 2024

Given a string s, the task is to check if it is a binary string or not. A binary string is a string which only contains the characters '0' and '1'.

Examples:

Input: s = "01010101010"
Output: true
Input: s = "geeks101"
Output: false

Approach:

The idea is to iterate over all the characters of the string and if we encounter a character other than '0' or '1', then the input string is not a binary string. Otherwise, if all the characters are either '0' or '1', then the input string is a binary string.

C++

// C++ Program to check if a string is
// binary string or not

#include <iostream>
using namespace std;

bool isBinary(string &s) {
    for (int i = 0; i < s.length(); i++) {

        // Check if the character is neither
        // '0' nor '1'
        if (s[i] != '0' && s[i] != '1') {
            return false;
        }
    }
    return true;
}

int main() {
    string s = "01010101010";
    cout << (isBinary(s) ? "true" : "false");
    return 0;
}

// C Program to check if a string is 
// binary string or not

#include <stdio.h>
#include <string.h>
#include <stdbool.h>

bool isBinary(char *s) {
    for(int i = 0; i < strlen(s); i++) {
      
        // Check if the character is neither 
        // '0' nor '1'
        if(s[i] != '0' && s[i] != '1') {
            return false;  
        }
    }
    return true; 
}

int main() {
    char s[] = "01010101010";
    printf(isBinary(s) ? "true" : "false");
    return 0;
}

Java

// Java Program to check if a string is 
// binary string or not

class GfG {
    static boolean isBinary(String s) {
        for (int i = 0; i < s.length(); i++) {
          
            // Check if the character is neither 
            // '0' nor '1'
            if (s.charAt(i) != '0' && s.charAt(i) != '1') {
                return false;
            }
        }
        return true;
    }

    public static void main(String[] args) {
        String s = "01010101010";
        System.out.println(isBinary(s));
    }
}

Python

# Python Program to check if a string is 
# binary string or not

def isBinary(s):
    for i in range(len(s)):
      
        # Check if the character is neither 
        # '0' nor '1'
        if s[i] != '0' and s[i] != '1':
            return False
    return True

s = "01010101010"
print("true" if isBinary(s) else "false")

// C# Program to check if a string is 
// binary string or not

using System;

class GfG {
    static bool isBinary(string s) {
        for (int i = 0; i < s.Length; i++) {
      
            // Check if the character is neither 
            // '0' nor '1'
            if (s[i] != '0' && s[i] != '1') {
                return false;
            }
        }
        return true;
    }

    static void Main() {
        string s = "01010101010";
        Console.WriteLine(isBinary(s) ? "true" : "false");
    }
}

JavaScript

// JavaScript Program to check if a string is 
// binary string or not

function isBinary(s) {
    for (let i = 0; i < s.length; i++) {
      
        // Check if the character is neither 
        // '0' nor '1'
        if (s[i] !== '0' && s[i] !== '1') {
            return false;
        }
    }
    return true;
}

let s = "01010101010";
console.log(isBinary(s));