특정한 값이 배열에 존재 하는지 체크(includes())

const array1 = [1, 2, 3];

console.log(array1.includes(2));
// Expected output: true



const pets = ['cat', 'dog', 'bat'];

console.log(pets.includes('cat'));
// Expected output: true

console.log(pets.includes('at'));
// Expected output: false