javascript check if a value exists in an array code example

Example 1: javascript method to see if item exists in array

var fruits = ["Apple", "Banana", "Mango", "Orange", "Papaya"];
    
    // Check if a value exists in the fruits array
    if(fruits.indexOf("Mango") !== -1){
        alert("Value exists!")
    } else{
        alert("Value does not exists!")
    }

Example 2: check value exist in array javascript

[1, 2, 3].includes(2);     // true
[1, 2, 3].includes(4);     // false
[1, 2, 3].includes(1, 2);  // false (second parameter is the index position in this array at which to begin searching)

Example 3: how to check if item is in list js

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

Example 4: see if array contains array javascript

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