JavaScript Program to Check if a String Contains any Whitespace Characters

In this article, we are given a string str, you need to find whether the given string contains whitespace characters or not in JavaScript. Whitespaces can occur at any position whether at the beginning or in between or at the end of the string.

Example 1:

Input:
str = Hi I am a Geek 
Output:
The string contains whitespace characters
Explanation: 
In the input string "Hi I am a geek" there are 4 whitespace characters which is shown by "_" :
Hi_I_am_a_Geek
So we return "The string contains whitespace characters"

Example 2:

Input:
str = helloWorld
Output:
The string does not contains whitespace characters

Examples of Checking if a String Contains any Whitespace Characters

1.Using regular expressions

To determine whether a string contains whitespace characters we can make use of regular expressions. A regular expression (regex) is a sequence of characters that define a search pattern. The “\s” metacharacter is used to match the whitespace character.

Example: Below is the implementation of the approach

Javascript

function checkWhitespace(str) {
    return /\s/.test(str);
}
let str = "Hi I am a Geek";
if (checkWhitespace(str)) {
    console.log(
        "The string contains whitespace characters."
    );
} else {
    console.log(
        "The string does not contain whitespace characters."
    );
}

Output

The string contains whitespace characters.

2.Using JavaScript Sets

• Create a new Set which contains whitespace characters i.e. space, \n, \t.
• Iterate over the string and check whether the set contains any character of the string in it.
• If it contains any character of the string it means that the string contains whitespace characters.
• Return true else return false.

Example: Below is the implementation of the approach

Javascript

function checkWhitespace(str) {
    let whitespace = new Set([" ", "\t", "\n"]);
    for (let i = 0; i < str.length; i++) {
        if (whitespace.has(str[i])) {
            return true;
        }
    }
    return false;
}

let str = "GeeksforGeeks";
if (checkWhitespace(str)) {
    console.log(
        "The string contains whitespace characters."
    );
} else {
    console.log(
        "The string does not contain whitespace characters."
    );
}

Output

The string does not contain whitespace characters.

3.Using for loop

In this we will iterates over each character in the string using a for loop and checks if character is a whitespace character or not. If its whitespace character then we will return true else return false.

Example: In this example we checks if a string contains any whitespace characters by iterating through each character, returning true if a whitespace character is found, else false.

JavaScript

function containsWhitespace(str) {
    for (let i = 0; i < str.length; i++) {
        if (str[i] === " ") {
            return true; // Found a whitespace character
        }
    }
    return false; // No whitespace characters found
}

let str = "GeeksFor  Geeks";

console.log;
if (containsWhitespace(str)) {
    console.log(
        "The string contains whitespace characters"
    );
} else {
    console.log(
        "The string does not contains whitespace characters"
    );
}

Output

The string contains whitespace characters