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JavaScript: Concatenate a specific string for a specific number of times

JavaScript String: Exercise-13 with Solution

Repeat String

Write a JavaScript function to concatenate a given string n times (default is 1).

Test Data:
console.log(repeat('Ha!'));
console.log(repeat('Ha!',2));
console.log(repeat('Ha!',3));
"Ha!"
"Ha!Ha!"
"Ha!Ha!Ha!"

Visual Presentation:

JavaScript: Concatenate a specific string for a specific number of times

Sample Solution:

JavaScript Code:

// Define a function called repeat that takes a string str and an optional count parameter
repeat = function repeat(str, count) {
    // If count parameter is not provided, set it to 1
    if(typeof(count) == "undefined") {
    count =1;
  }
  // Return an empty string if count is less than 1, otherwise repeat the string count times
  return count < 1 ? '' : new Array(count + 1).join(str);
    }
// Test the repeat function with different inputs and print the results to the console
console.log(repeat('Ha!'));
console.log(repeat('Ha!',2));
console.log(repeat('Ha!',3));

Output:

Ha!
Ha!Ha!
Ha!Ha!Ha!

Explanation:

In the exercise above,

  • The "repeat()" function takes two parameters: 'str' (the string to repeat) and 'count' (the number of times to repeat the string).
  • If the 'count' parameter is not provided, it defaults to 1.
  • The function checks if 'count' is less than 1. If so, it returns an empty string, indicating no repetition.
  • If 'count' is 1 or greater, the function creates an array with a length of 'count + 1' and then joins the elements of the array with the 'str' string to repeat it 'count' times.
  • The results of calling the "repeat()" function with different inputs are printed to the console for testing.

Flowchart:

Flowchart: JavaScript- Concatenate a specific  string for a specific number of times

Live Demo:

See the Pen JavaScript Concatenate a specific string for a specific number of times - string-ex-13 by w3resource (@w3resource) on CodePen.


For more Practice: Solve these Related Problems:

  • Write a JavaScript function that repeats a string a specified number of times using a loop.
  • Write a JavaScript function that employs recursion to repeat a string n times.
  • Write a JavaScript function that uses the repeat() method if available, and falls back to a custom implementation otherwise.
  • Write a JavaScript function that validates the count parameter and returns an error if it is not a positive integer.

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