w3resource

JavaScript: Create a specified number of elements and pre-filled string value array

JavaScript Array: Exercise-37 with Solution

Write a JavaScript function to create a specified number of elements with a pre-filled string value array.

Test Data:
console.log(array_filled(3, 'default value'));
["default value", "default value", "default value"]
console.log(array_filled(4, 'password'));
["password", "password", "password", "password"]

Sample Solution:

JavaScript Code :

// Function to create a new array with 'n' elements, each initialized to the specified 'val'
function array_filled(n, val) {
    // Use Array.apply to create an array-like object with 'n' undefined elements
    // and then use map to fill each element with the specified 'val' converted to a string
    return Array.apply(null, Array(n)).map(String.prototype.valueOf, val);
}

// Output the result of array_filled with 'n=3' and 'val='default value''
console.log(array_filled(3, 'default value'));

// Output the result of array_filled with 'n=4' and 'val='password''
console.log(array_filled(4, 'password'));

Sample Output:

["default value","default value","default value"]
["password","password","password","password"]

Flowchart:

Flowchart: JavaScript: Create a specified number of elements and pre-filled string value array

ES6 Version:

// Function to create a new array with 'n' elements, each initialized to the specified 'val'
const array_filled = (n, val) =>
  // Use Array.from to create an array with 'n' undefined elements
  Array.from({ length: n }, () => String(val));

// Output the result of array_filled with 'n=3' and 'val='default value''
console.log(array_filled(3, 'default value'));

// Output the result of array_filled with 'n=4' and 'val='password''
console.log(array_filled(4, 'password'));

Live Demo:

See the Pen JavaScript - Create a specified number of elements and pre-filled string value array-array-ex- 37 by w3resource (@w3resource) on CodePen.


Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript function to create a specified number of elements and pre-filled numeric value array.
Next: Write a JavaScript function to move an array element from one position to another.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.