JavaScript: Return true if a value is an empty object, collection, map or set, has no enumerable properties or is any type that is not considered a collection

JavaScript fundamental (ES6 Syntax): Exercise-200 with Solution

Write a JavaScript program that returns true if a value is an empty object, collection, map or set. It has no enumerable properties or is of any type not considered a collection.

• Check if the provided value is null or if its length is equal to 0.

Sample Solution:

JavaScript Code:

// Define a function 'isEmpty' that checks if the given value 'val' is empty
const isEmpty = val =>
  // Check if 'val' is null, undefined, an empty array, an empty object,
  // an empty Map, an empty Set, or an empty string
  val == null || !(Object.keys(val) || val).length;

// Test cases to check if the values are empty
console.log(isEmpty(new Map()));        // true (the Map is empty)
console.log(isEmpty(new Set()));        // true (the Set is empty)
console.log(isEmpty([]));               // true (the array is empty)
console.log(isEmpty({}));               // true (the object is empty)
console.log(isEmpty(''));               // true (the string is empty)
console.log(isEmpty([1, 2]));           // false (the array is not empty)
console.log(isEmpty({ a: 1, b: 2 }));   // false (the object is not empty)
console.log(isEmpty('text'));           // false (the string is not empty)
console.log(isEmpty(123));              // true (numbers are considered empty)
console.log(isEmpty(true));             // true (booleans are considered empty)

Output:

true
true
true
true
true
false
false
false
true
true

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-200-1 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

Previous: Write a JavaScript program that will return true if the given number is even, false otherwise.
Next: Write a JavaScript program to check if the first numeric argument is divisible by the second one.