check if a string is contained in another string javascript code example

Example 1: javascript string includes

'Blue Whale'.includes('blue')  // returns false

Example 2: string contains in javascript

const string = "foo";
const substring = "oo";

console.log(string.includes(substring));

Example 3: javascript check if string contains a text substring

stringVariable.includes("Your Text");

Example 4: js check if string contains character

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