JavaScript Map has() Method
The Map.has() method in Javascript is used to check whether an element with a specified key exists in a map or not. It returns a boolean value indicating the presence or absence of an element with a specified key in a map. The Map.has() method takes the key of the element to be searched as an argument and returns a boolean value. It returns true if the element exists in the map else it returns false if the element doesn’t exist.
Syntax:
mapObj.has(key)
Parameters Used:
- key: It is the key of the element of the map which has to be searched.
Return Value: The Map.has() method returns a boolean value. It returns true if the element exists in the map else it returns false if the element doesn’t exist.
Examples of the above function are provided below.
Example 1: In this example, a map object “myMap” has been created with a single [key, value] pair, and the Map.has() method is used to check whether an element with the key ‘0’ exists in the map or not.
javascript
// creating a map object let myMap = new Map(); // Adding [key, value] pair to the map myMap.set(0, 'geeksforgeeks'); // displaying whether an element with // the key '0' exists in the map or not // using Map.has() method console.log(myMap.has(0)); |
Output:
true
Example 2: In this example, a map object “myMap” has been created with three [key, value] pairs, and the Map.has() method is used to check whether an element with the key ‘0’ and ‘3’ exists in the map or not.
javascript
// creating a map object let myMap = new Map(); // Adding [key, value] pair to the map myMap.set(0, 'geeksforgeeks'); myMap.set(1, 'is an online portal'); myMap.set(2, 'for geeks'); // displaying whether an element with the // key '0' and '3' exists in // the map or not using Map.has() method console.log(myMap.has(0)); console.log(myMap.has(3)); |
Output:
true false
We have a complete list of Javascript Map methods, to check those please go through this JavaScript MapComplete Reference article.
Supported Browsers:
- Chrome 38 and above
- Edge 12 and above
- Firefox 13 and above
- Internet Explorer 11 and above
- Opera 25 and above
- Safari 8 and above
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