check if array contains element javascript code example

Example 1: js test if array

if(Array.isArray(myVarToTest)) {
	// myVatToTest is an array
} else {
	// myVarToTest is not an array
}

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: javascript array contains

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

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: javascript check if array is in array

var array = [1, 3],
    prizes = [[1, 3], [1, 4]],
    includes = prizes.some(a => array.every((v, i) => v === a[i]));

console.log(includes);