JAVASCRIPT

in array in js

var letters = ["A", "B", "C", "D"];

var result = letters.includes("A");
// result will be TRUE or FALSE

javascript element in array

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

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

js in_array

var a = [1, 2, 3];
a.includes(2); // true 
a.includes(4); // false

js arrays in arrays

// This is known as a 2-dimensional array (or matrix)
let tester = [
	[2,5], // 0
	[10,6] // 1
/*   ^  ^
     0  1
*/
];

// Get the element on the first row and the second column
console.log(tester[0][1]);

// iterate through each row and return the first column
for(let i = 0; i < tester.length;i++){
	console.log(tester[i][0])
}