check if array contains string js code example

Example 1: javascript array contains

var colors = ["red", "blue", "green"];
var hasRed = colors.includes("red"); //true
var hasYellow = colors.includes("yellow"); //false

Example 2: how to check if item is in list js

var myList=["a", "b", "c"];
mylist.includes("d")//returns true or false

Example 3: js array contains

let fruits = ["Banana", "Orange", "Apple", "Mango"];
let do_contain = fruits.includes("Mango"); // contain: true

Example 4: 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 5: see if array contains array javascript

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

Example 6: 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"]));