JavaScript map entries() method returns an object of a new map iterator. The new iterator object contains the [key, value] pairs for each element in the Map object in insertion order.
mapObj.entries()JavaScript map entries
Simple example code.
<!DOCTYPE html>
<html>
<body>
<script>
const map1 = new Map();
map1.set('0', 'foo');
map1.set(1, 'bar');
const itr = map1.entries();
console.log(itr.next().value);
console.log(itr.next().value);
console.log(itr)
</script>
</body>
</html>Output:
More example
const myMap = new Map();
myMap.set('0', 'foo');
myMap.set(1, 'bar');
myMap.set({}, 'baz');
const mapIter = myMap.entries();
console.log(mapIter.next().value); // ["0", "foo"]
console.log(mapIter.next().value); // [1, "bar"]
console.log(mapIter.next().value); // [Object, "baz"]
Let’s see the same example using for loop.
<script>
var map = new Map();
map.set(1,"jQuery");
map.set(2,"AngularJS");
map.set(3,"Bootstrap");
var itr = map.entries();
for(i=0;i<map.size;i++)
{
console.log(itr.next().value);
}
</script>Output:
Array [ 1, "jQuery" ]
Array [ 2, "AngularJS" ]
Array [ 3, "Bootstrap" ]Do comment if you have any doubts or suggestions on this Js map method topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version