Javascript Map Function For Object

If you want to keep the original objects unaltered, then use array#map and copy the objects using object#assign: This useful array method creates a new array with the results of calling a provided function on every element in. Foreach() calls a function for each key/value pair in a map:

Here, we have used numbers as keys and strings to represent that number as value. Callbackfn is invoked with three arguments: It creates a new array without modifying the elements of the original array.

To iterate over an object, use the object.keys () method to get an array of the object's keys and call the map () method on the array of keys.

Map () does not change the original array. New map() creates a new map: The array filter () method the array foreach () method syntax The object.map is not a function error occurs because the map method is not implemented on objects.