javascript check if word is in array code example

Example 1: javascript element in array

var fruits = ["Banana", "Orange", "Apple", "Mango"];

var n = fruits.includes("Mango");

Example 2: javascript array contains

var fruits = ["Banana", "Orange", "Apple", "Mango"];
var n = fruits.includes("Mango");

Example 3: javascript check if in array

var extensions = ["image/jpeg","image/png","image/gif"];          
if(extensions.indexOf("myfiletype") === -1){
	alert("Image must be .png, .jpg or .gif");
}

Example 4: 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"]));