check if something is in array code example

Example 1: see if array contains array javascript

const found = arr1.some(r=> arr2.indexOf(r) >= 0)

Example 2: check items in array javascript

function checkAllEven(arr) {
  return arr.every(function(x){
	 return	x % 2 === 0
	})
}

//using "every" to check every item in array.