如何在函数中传递参数？

Question

有没有办法跳过一个函数或构造函数中的参数。我相信有，但是每当我尝试用构造函数来做时，我都会收到一条错误消息。

的Javascript

function Black(race, nation){ 
     this.race = race ||"black"; 
     this.nation = nation || "unknown"; 


    } 

    black1 = new Black(,"America"); 
    black2 = new Black( ,"UK"); 
    black3 = new Black(,"S America"); 

    console.log(black1, black2, black3); 

Answer 1

使用var black1 = new Black(null, "America");