交换两个变量，不第三方变量

Posted 2020-10-17 ouruixi

交换2个number类型的变量的值，不能使用第三方变量

var num1 = 10;
    var num2 = 20;

    //先相加再相减
    num1 = num1 + num2; //num1 = 30;   num2 = 20;
    num2 = num1 - num2; //num1 = 30;   num2 = 10;
    num1 = num1 - num2; //num1 = 20;   num2 = 10;

    console.log(num1); //20
    console.log(num2); //10