Study.js

// var a = 5;  //  var is old-fashioned, changed to let or const
// let b = 10; // New Seasoned . can be changed
// const c = 15; // new Seasoned . cannot be changed
// console.log(a, b, c);

//------------------------------
//data type
// const a = 5 ; //    number
// const b = "handsome" ;  // string
// const c = true ;    // boolean

// console.log(a ,typeof a);
// console.log(b ,typeof b);
// console.log(c ,typeof c);

//------------------------------
//operator + - * / %

let a = 5;
let b = 2;
console.log(a + b); // addition cộng 
console.log(a - b); // subtraction trừ
console.log(a * b); // multiplication   nhân
console.log(a / b); // division chia
console.log(a % b); // modulus (remainder) chia lấy dư