array contains key javascript code example

Example 1: 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.

Example 2: check if array does not contain string js

function checkInput(input, words) {
 return words.some(word => input.toLowerCase().includes(word.toLowerCase()));
}

console.log(checkInput('"Definitely," he said in a matter-of-fact tone.', 
["matter", "definitely"]));