JavaScript .size

The .size property returns the number of entries inside of a Map object.

Syntax

map.size;

Since .size is a property of Map, no parentheses are needed.

Example

Assuming there is a map of fruits, the number of keys can be checked with the .size property:

const fruits = new Map([
  ['Apples', 5],
  ['Oranges', 8],
]);

console.log(fruits.size); // Output: 2

Copy to clipboard
Copy to clipboard

Codebyte Example

The following example uses the size property to confirm the number of elements in a map after deleting a key-value pair.

Visit us
Visit us
Hide code
Code
Output
Hide output
Loading...
Copy to your clipboard
Copy Codebyte
Run