在JavaScript对象中为键值分配另一个键值 | 在JavaScript对象中为键值分配另一个键值

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问题描述

例如，我知道可以在Javascript中将键值设置为先前的键值

I know its possible to set a key value with a preceding key value in Javascript for example

var obj = {
            one: "yes",
            two: obj.one
          }

obj [two]现在等于是"

obj[two] is now equal to "yes"

当按键在功能中时，如何设置值

How do i go about setting the value when the keys are in a function

var obj = {
             one: function () {
                  return(
                     two: "yes"
                     three: ?? //I want to set three to the value of two
                  )
             }
          }

我想让三个包含两个值，即obj.one()应该返回{两个:是"，三个:是"}

I want to have three contain the value of two i.e obj.one() should return {two: "yes", three: "yes"}

推荐答案

您的第一个代码也不起作用.它抛出TypeError: obj is undefined.

Your first code doesn't work neither. It throws TypeError: obj is undefined.

您可以使用

var obj = new function(){
  this.one = "yes",
  this.two = this.one
}; // { one: "yes", two: "yes" }

对于第二个，您可以使用

For the second one, you can use

var obj = {
  one: function () {
    return new function() {
      this.two = "yes",
      this.three = this.two
    };
  }
};
obj.one(); // { two: "yes", three: "yes" }
obj.one() === obj.one(); // false

请注意，每次调用one都会产生该对象的新副本.如果要重用上一个，

Note each call of one will produce a new copy of the object. If you want to reuse the previous one,

var obj = {
  one: (function () {
    var obj = new function() {
      this.two = "yes",
      this.three = this.two
    };
    return function(){ return obj }
  })()
};
obj.one(); // { two: "yes", three: "yes" }
obj.one() === obj.one(); // true

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