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
var myString = 'this is my string';
myString.indexOf('string');
// -> 11
myString.indexOf('hello');
// -> -1
String.prototype.includes is, as you write, not supported in Internet Explorer (or Opera). nstead you can use String.prototype.indexOf. #indexOf returns the index of the first character of the substring if it is in the string, otherwise it returns -1. (Much like the Array equivalent)
https://developer.mozilla.org/ko/docs/Web/JavaScript/Reference/Global_Objects/Array/includes
https://stackoverflow.com/questions/36574351/includes-not-working-in-internet-explorer
감사합니다!!!
덕분에 문제 해결 금방 했습니다