SOURCE

var a = 4
var b = 5

console.log(a + b) //算术和位运算符  加
console.log(a - b) //算术和位运算符  减
console.log(a * b) //算术和位运算符  乘
console.log(a / b) //算术和位运算符  除
console.log(b % 4) //取余数

console.log(a++ ) // 自加
console.log(++a )
console.log(a--) //自减
console.log(--a)

a = 6 // 赋值
console.log(a)
console.log(a+=b) //a = a + b 
console.log(a-=b) //a = a - b 
console.log(a*=b) //a = a * b 
console.log(a/=b) //a = a / b 
console.log(a%=b) //a = a % b