js 如何删除对象中的一个属性

xiongzhengxiang

于 2011-10-17 09:00:31 发布

阅读量3.5w

点赞数

分类专栏： JS 文章标签： object

本文链接：https://blog.youkuaiyun.com/xiongzhengxiang/article/details/6880062

版权

JS 专栏收录该内容

152 篇文章

订阅专栏

本文深入探讨了在JavaScript中使用delete操作符删除属性的重要性，解释了仅设置属性值为undefined或null与真正删除属性之间的关键区别，并通过实例演示了如何正确地删除对象属性。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Deleting Properties

The only way to actually remove a property from an object is to use thedelete operator; setting the property to undefined or null only remove the value associated with the property, but not the key.

var obj = {
    bar: 1,
    foo: 2,
    baz: 3
};
obj.bar = undefined;
obj.foo = null;
delete obj.baz;

for(var i in obj) {
    if (obj.hasOwnProperty(i)) {
        console.log(i, '' + obj[i]);
    }
}

The above outputs both bar undefined and foo null - only baz was removed and is therefore missing from the output.