how to know what string you have in js code example

Example 1: includes in javascript

var colors = ['yellow', 'red', 'pink'];
var string = 'yellow and red are pretty cool';

// outputs false
console.log(colors.include('blue');
// outputs true
console.log(string.includes('yellow');

Example 2: js check if string contains character

if (your_string.indexOf('hello') > -1)
{
  alert("hello found inside your_string");
}