ES6/ES7中“可选"对象键的简洁/简洁语法? [英] Succinct/concise syntax for 'optional' object keys in ES6/ES7?

问题描述

ES6/ES7中已经有很多酷功能用于定义Javascript对象.但是，以下模式在Javascript中很常见:

There are already a lot of cool features in ES6/ES7 for defining Javascript objects. However, the following pattern is common in Javascript:

const obj = { 
  requiredKey1: ..., 
  requiredKey2: ... 
};

if (someCondition) { 
  obj.optionalKey1 = ...;
}

有没有一种方法可以同时使用可选键和必需键来定义对象?

Is there a way to define the object all at once with both optional and required keys?

推荐答案

您可以使用对象传播以具有可选属性.

You can use object spread to have an optional property.

注意:对象保留/扩展是ECMAScript的第4阶段建议.您可能需要 babel转换才能使用它.

Note: Object Rest/Spread is a stage 4 proposal for ECMAScript. You might need the babel transform to use it.

let flag1 = true;
let flag2 = false;

const obj = { 
  requiredKey1: 1, 
  requiredKey2: 2,
  ...(flag1 && { optionalKey1: 5 }),
  ...(flag2 && { optionalKey2: 6, optionalKey3: 7 }),
  ...(flag1 && { optionalKey4: 8, optionalKey5: 9 })
};

console.log(obj);

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