递增运算符的练习

后置自增  先表达式返回值原值   后面变量再加1

 

    var a = 10;
    ++a; //++a  11     a = 11
    var b = ++a + 2; //a= 12   ++a = 12
    console.log(b); //14

    var c = 10;
    c++; //c++  + 2 //c++  = 11    c  = 12
    var d = c++ + 2;
    console.log(d);

    var e = 10;
    var f = e++ + ++e;
    console.log(f);