Javascript Map Over Array

The method takes an initial value to work with, so we give an empty array [] as the initial value. Const numbers1 = [45, 4, 9, 16, 25]; You're not modifying your original array.

Try it syntax // arrow function map((element) => { /*. The reduce() method is used to reduce the array to a single value by executing a reducer function on each element of the array, resulting in a single output value. Example // create a map const fruits = new map ( [ [apples, 500], [bananas, 300], [oranges, 200] ]);

This.undergroundgeojson.features.map(u => { console.log(u) // this will print each object within `features` return u;

I believe you are trying to iterate through the array of objects in this.undergroundgeojson.features? Function test(key, values) { this.key = key; It creates a new array without modifying the elements of the original array. Map () calls a function once for each element in an array.