// includes(): It takes a substring argument and it check if substring argument exists in the string. includes() returns a boolean. It checks if a substring exist in a string and it returns true if it exists and false if it doesn't exist.

let string = '30 Days Of JavaScript'

console.log(string.includes('Days')) // true

console.log(string.includes('days')) // false

console.log(string.includes('Script')) // true

console.log(string.includes('script')) // false

console.log(string.includes('java')) // false

console.log(string.includes('Java')) // true

let country = 'Finland'

console.log(country.includes('fin')) // false

console.log(country.includes('Fin')) // true

console.log(country.includes('land')) // true

console.log(country.includes('Land')) // false