Javascript Map With Spread Operator

Get () gets the value for a key in a map. Array, string , map, set, dom nodes. Spread operator is a very simple and powerful feature introduced in es6 standard of javascript, which helps you write nicer and shorter code.

Using the spread (.) operator with map() i have been learning react and one of the common patterns from the books i have been looking at suggests using functional programming principles to avoid mutating state directly. Spread syntax can be used when all elements from an object or array need to be included in a list of some kind. A two dimensional array or another map object.

In it's simplest form, the spread operator lets you use an array where multiple elements or arguments are expected, for your example something like.

The ternary operator, the es6 map/reduce and the spread operator are powerful constructs. Foreach () calls a function for each key/value pair in a map. When we invoke the function, we pass it all the values in the array using the spread syntax. We use the javascript spread operator to include all existing object property values along with the new properties that need to be added to object entries.