let string = 'JavaScript'

console.log(string.substring(0,4))     // Java
console.log(string.substring(4,10))    // Script
console.log(string.substring(4))       // Script

let country = 'Finland'

console.log(country.substring(0, 3))   // Fin
console.log(country.substring(3, 7))   // land
console.log(country.substring(3))      // land