how to check value in array in javascript code example

Example 1: get if there is a value in an array node js

myArray = Array(/*element1, element2, etc...*/);

// If the array 'myArray' contains the element 'valueWeSearch'
if(myArray.includes(valueWeSearch))
{
 	// Do something
}

Example 2: javascript is int in array

[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: see if array contains array javascript

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

Example 4: 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);

Example 5: check items in array javascript

function checkAllEven(arr) {
  return arr.every(function(x){
	 return	x % 2 === 0
	})
}

//using "every" to check every item in array.