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JavaScript: Repeat a string a specified times

JavaScript String: Exercise-21 with Solution

Write a JavaScript function to repeat a string a specified times.

Test Data:
console.log(repeat_string('a', 4));
console.log(repeat_string('a'));
Output:
"aaaa"
"Error in string or count."

Pictorial Presentation:

JavaScript: Repeat a string a specified times

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Write a JavaScript function to repeat a string a specified times.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function repeat_string(string, count) 
  {
    if ((string == null) || (count < 0) || (count === Infinity) || (count == null))
      {
        return('Error in string or count.');
      }
        count = count | 0; // Floor count.
    return new Array(count + 1).join(string);
  }

console.log(repeat_string('a', 4));
console.log(repeat_string('a'));
console.log(repeat_string('a', -2));
console.log(repeat_string('a', Infinity));

Sample Output:

aaaa
Error in string or count.
Error in string or count.
Error in string or count.

Flowchart:

Flowchart: JavaScript: Repeat a string a specified times

Live Demo:

See the Pen JavaScript - common-editor-exercises by w3resource (@w3resource) on CodePen.


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Previous:Write a JavaScript function that can pad (left, right) a string to get to a determined length.
Next:Write a JavaScript function to get a part of string after a specified character.

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JavaScript: Tips of the Day

How to check whether a string contains a substring in JavaScript?

ECMAScript 6 introduced String.prototype.includes:

const string = "foo";
const substring = "oo";

console.log(string.includes(substring));

includes doesn't have Internet Explorer support, though. In ECMAScript 5 or older environments, use String.prototype.indexOf, which returns -1 when a substring cannot be found:

var string = "foo";
var substring = "oo";

console.log(string.indexOf(substring) !== -1);

Ref: https://bit.ly/3fFFgZv