JavaScript - reverse string (English letters)

In this short article, we would like to show you how reverse strings using JavaScript.

In practice string reversion problem is very comples when we work on emojis, surrogate characters, Asian characters, etc. Some solutions for that kind of strings reversion was shown in this article.

In the below you can find different solutions.

1. split-reverse-join example

// ONLINE-RUNNER:browser;

function reverseString(text) {
    var characters = text.split('');
    var reversion = characters.reverse();
    return reversion.join('');
}


// Usage example:

var text = 'ABC';
var reversion = reverseString(text);

console.log(reversion);  // CBA

Warning: this solutuion doesn't work with all emojis and Asian characters.

Output:

CBA

2. Reverse string with iteration example

2.1. for...of solutuion

This solution should be used when we work on more comples unicode characters like emoji.

// ONLINE-RUNNER:browser;

function reverseString(text) {
    let result = '';
    for (const character of text) {
        result = character + result;
    }
    return result;
}


// Usage example:

var text = 'Hi there ! 💻🙂😀😋';
var reversion = reverseString(text);

console.log(text);       // Hi there ! 💻🙂😀😋
console.log(reversion);  // 😋😀🙂💻 ! ereht iH

Warnings:

• this solution works under ES6+,
• this solutuion doesn't work with all emojis and Asian characters.

2.2. classic for solution

// ONLINE-RUNNER:browser;

function reverseString(text) {
    var result = '';
    for(var i = text.length - 1; i > -1; --i) {
        result += text[i];
    }
    return result;
}


// Usage example:

var text = 'ABC';
var reversion = reverseString(text);

console.log(reversion);  // CBA

Warning: this solutuion doesn't work with all emojis and Asian characters.

3. String.prototype.reverse method prototype

// ONLINE-RUNNER:browser;

if (String.prototype.reverse == null) {
    String.prototype.reverse = function() {
        var result = '';
        for (var i = this.length - 1; i > -1; --i) {
            result += this[i];
        }
        return result;
    }
}


// Usage example:

var text = 'ABC';
var reversion = text.reverse();

console.log(reversion);  // CBA

Note: in this case String object is extended of new reverse method.

Warning: this solutuion doesn't work with all emojis and Asian characters.

Output:

CBA

See also

1. JavaScript - reverse string that contains emoji, surrogate characters and Asian characters