写法:
- 前自增: ++num
- 后自增:num++
特点
- 共同点:对于变量自身而言是没有任何影响的,都是在自身的基础上+1
- 不同点:在变量的赋值过程中,前自增是先自增在赋值,后自增是先赋值在自增
常规示例
var num = 10;
var res = ++num;
console.log(num); // 11
console.log(res);// 11
var num1 = 10;
var res1 = num1++;
console.log(num1); // 11
console.log(res1);// 10
高级示例
var n1 = 10;
var res = n1++ + n1++;
console.log("n1:" + n1);//12
console.log("res:" + res);//21
var n2 = 10;
var res2 = ++n2 + ++n2;
console.log("n2:" + n2);//12
console.log("res2:" + res2);//23
var n3 = 10;
var res3 = ++n3 + n3++;
console.log("n3:" + n3);//12
console.log("res3:" + res3);//22
var n4 = 10;
var res4 = n4++ + ++n4;
console.log("n4:" + n4);//12
console.log("res4:" + res4);//22
