使用删除属性而不影响父对象

Question

这是两个名为和 的对象：primarysecondary

var primary = {"gonna":3,"lol":114,"wouldn":2,"know":6,"lowkey":2,"man":5};
var secondary = primary;

当我使用delete secondary['lol'];它时，它会从两个对象中删除该属性：jsfiddle

我的问题是：如何删除属性secondary而不将其删除primary？

Answer 1

secondary引用与 相同的对象primary。primary如果您想将它们分开，则需要创建一个副本。

有些库（例如Lodash）具有实用功能，允许您克隆对象（下面的示例），但也有其他方法。

var primary = {"gonna":3,"lol":114,"wouldn":2,"know":6,"lowkey":2,"man":5};
var secondary = _.clone(primary);

delete secondary.lol;

document.write(JSON.stringify(primary));
document.write('<br>');
document.write(JSON.stringify(secondary));

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.10.1/lodash.js"></script>