Javascript Array Map Object

The map is a new type introduced in es6 that holds key and value pairs using the hash map data structure. Clear() removes all the elements from a map: Use the map () constructor to create a new map.

To convert an array of objects to a map: Delete() removes a map element specified by a key: Var numbers = [ 1, 4, 9 ];

Generally map () method is used to iterate over an array and calling function on every element of array.

The array filter () method the array foreach () method syntax The following code takes an array of numbers and creates a new array containing the square roots of the numbers in the first array. The final returned map uses the unique values from the test function as keys, which can be used to get the array of elements in each group. Var numbers = [ 1, 4, 9 ];