javascript - 对象常量/初始化程序中的自引用(Self-references in object literals / initializers)

Question

Is there any way to get something like the following to work in JavaScript?(有什么办法可以使以下内容在JavaScript中起作用？)

var foo = { a: 5, b: 6, c: this.a + this.b // Doesn't work }; In the current form, this code obviously throws a reference error since this doesn't refer to foo .(在当前形式中，该代码明显抛出一个参考错误，因为this不是指foo 。) But is there any way to have values in an object literal's properties depend on other properties declared earlier?(但是， 是否有任何方法可以使对象文字的属性值取决于先前声明的其他属性？)   ask by kpozin translate from so

Answer 1

Well, the only thing that I can tell you about are getters:(好吧，我唯一能告诉您的就是吸气剂：)

var foo = { a: 5, b: 6, get c() { return this.a + this.b; } } console.log(foo.c) // 11 This is a syntactic extension introduced by the ECMAScript 5th Edition Specification, the syntax is supported by most modern browsers (including IE9).(这是ECMAScript 5th Edition规范引入的语法扩展，大多数现代浏览器（包括IE9）都支持该语法。)