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Repeat String in JavaScript?

Javascript Web Development Front End Technology Object Oriented Programming

JavaScript provides multiple ways to repeat a string. The most modern approach is using the built-in repeat() method, but you can also use older techniques like Array.join().

Using String.repeat() (Recommended)

The String.repeat() method is the standard way to repeat strings in modern JavaScript:

<!DOCTYPE html>
<html>
<head>
    <title>String Repeat Example</title>
</head>
<body>
    <script>
        let str = "Hello ";
        let repeated = str.repeat(3);
        console.log(repeated);
        
        // More examples
        console.log("*".repeat(10));
        console.log("ABC".repeat(4));
    </script>
</body>
</html>

Hello Hello Hello 
**********
ABCABCABCABC

Using Array.join() Method

Before repeat() was available, developers used Array.join() to repeat strings:

<!DOCTYPE html>
<html>
<head>
    <title>Array Join Repeat</title>
</head>
<body>
    <script>
        function repeatString(str, count) {
            return new Array(count + 1).join(str);
        }
        
        console.log(repeatString("Hello ", 3));
        console.log(repeatString("-", 8));
    </script>
</body>
</html>

Hello Hello Hello 
--------

Extending String Prototype

You can extend the String prototype to add a custom repeat method:

<!DOCTYPE html>
<html>
<head>
    <title>String Prototype Extension</title>
</head>
<body>
    <script>
        String.prototype.repeatTimes = function(count) {
            return new Array(count + 1).join(this);
        };
        
        console.log("Hi ".repeatTimes(4));
        console.log("=".repeatTimes(15));
    </script>
</body>
</html>

Hi Hi Hi Hi 
===============

Comparison

Method	Browser Support	Performance	Readability
`String.repeat()`	ES6+ (Modern)	Best	Excellent
`Array.join()`	All browsers	Good	Moderate
Prototype extension	All browsers	Good	Good

Common Use Cases

<!DOCTYPE html>
<html>
<head>
    <title>Practical Examples</title>
</head>
<body>
    <script>
        // Creating separators
        console.log("=".repeat(30));
        
        // Padding strings
        let num = "42";
        let padded = "0".repeat(5 - num.length) + num;
        console.log(padded);
        
        // Creating patterns
        console.log("*-".repeat(10));
    </script>
</body>
</html>

==============================
00042
*-*-*-*-*-*-*-*-*-*-

Conclusion

Use String.repeat() for modern applications as it's cleaner and more efficient. Fall back to Array.join() only when supporting very old browsers.

AmitDiwan

Updated on: 2026-03-15T23:19:00+05:30

180 Views

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