var num1 = 100;
var num2 = 10;

//加减乘除
console.log(num1 + num2);//110
console.log(num1 - num2);//90
console.log(num1 * num2);1000
console.log(num1 / num2);10

//取余
console.log(num1 % num2);//0

//自增或自减运算符 相当于 当前值+1或者-1

var num3 = 20;
console.log(++num3);//num3 + 1 = 21
console.log(--num3);//num3 - 1 = 20

// 自增和自减有两种写法 ++num num++
//++在前，先自增再运算
//++在后，先运算再自增

var num4 = 10;
console.log(num4++);//10
console.log(++num4);//12