combine identical arrays and add nnumber properties js code example

Example 1: javascript concat two arrays

//ES6
const array3 = [...array1, ...array2];

Example 2: combine 2 arrays javascript

//ES6 using the spread operator
const itemsA = [ 'Lightsaber', 'Mockingjay pin', 'Box of chocolates' ];
const itemsB = [ 'Ghost trap', 'The One Ring', 'DeLorean' ]
const allItems = [ ...itemsA, ...itemsB ];