es6 check if item in array 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: 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: array includes

let storyWords = ['extremely', 'literally', 'actually', 'hi', 'bye', 'okay']
let unnecessaryWords = ['extremely', 'literally', 'actually' ];

let betterWords = storyWords.filter(function(word) {
  return !unnecessaryWords.includes(word);
});
console.log(betterWords) // ['hi' 'bye' 'okay]

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);