JavaScript Map object holds key-value pairs and remembers the original insertion order of the keys. A Map object holds key-value pairs where the keys can be any datatype.
To create a new Map, you use the following syntax:
let map = new Map([iterable]);Map Object JavaScript
Simple example code creates a new Map object.
<!DOCTYPE html>
<html>
<body>
<script >
const map1 = new Map();
map1.set('a', 1);
map1.set('b', 2);
map1.set('c', 3);
console.log(map1)
</script>
</body>
</html>Output:
More examples
const map1 = new Map();
map1.set('a', 1);
map1.set('b', 2);
map1.set('c', 3);
console.log(map1.get('a')); // 1
map1.set('a', 97);
console.log(map1.get('a')); // 97
console.log(map1.size); // 3
map1.delete('b');
console.log(map1.size); // 2Example map to the Object
var myObject = { 'a': 1, 'b': 2, 'c': 3 };
Object.keys(myObject).map(function(key, index) {
myObject[key] *= 2;
});
console.log(myObject);Output:
{
"a": 2,
"b": 4,
"c": 6
}Do comment if you have any doubts or suggestions on this JavaScript Map object basic topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version