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