how to check if the string is a member of an array javascript code example

Example 1: see if array contains array javascript

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

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"]));