object

How to deep copy a custom object in JavaScript?

假如想象 提交于 2020-01-21 06:33:50
问题 I've been surfing around here a while and still haven't found an answer that worked for me. Is there any way to deep copy a non-plain object in JS? I've tried jQuery.extend(true, {}, this) but it only cloned some of it, the rest remained as a reference to another object. 回答1: Here are 3 different methods for copying objects. Each method has pros and cons, so read through and pick the best for your situation Object.assign method Use Object.assign , which "is used to copy the values of all

Vue给对象新增属性展示没更新,值实际有更新

别说谁变了你拦得住时间么 提交于 2020-01-21 04:28:06
Vue-给对象新增属性:如果在实例创建之后添加新的属性到实例上,它不会触发视图更新。表现为该属性没有getter/setter,会随固有旧属性更新而更新 可以使用Vue.set(object, key, value)或this.$set(object, key, value) this.obj= Object.assign({}, this.obj, { a: 1, e: 2 }) 代替 Object.assign(this.obj, { a: 1, e: 2 }) 来源: CSDN 作者: Coding_Yeah 链接: https://blog.csdn.net/weixin_44135666/article/details/104048009

Java中Object类的各种方法详解

蹲街弑〆低调 提交于 2020-01-21 04:02:01
文章目录 1.registerNatives() 2.getClass() 3.hashCode() 4.equals(Object obj) 5.clone() 6.toString() 7.notify()、notifyAll() 8.wait(long timeout)、wait(long timeout, int nanos)、wait() 9.finalize() 1.registerNatives() 源码: private static native void registerNatives ( ) ; static { registerNatives ( ) ; } 我对这个方法暂时还不太理解,后面我补回来!这个跟JNI有关,而我工作中会用到JNI,虽然现在还不会用,哈哈哈!! 2.getClass() 源码: public final native Class < ? > getClass ( ) ; 首先,这个方法是被 final 修饰的,你平时写一个类,可以通过那个类的对象调用Object的这个方法, 所以说,被 final 修饰的方法,是可以被继承的,但是不能被重写。 方法注释是这么说的: 什么是运行时类? 我们通过eclipse写一段代码,不调试和运行,把它保存起来,会变成一个后缀为 .java 的文件,我们把它叫做源文件

jquery javascript remove object data from JSON object

霸气de小男生 提交于 2020-01-21 03:49:10
问题 I have JSON Object that looks something like the below object, this object can go on for days. So I am wondering is there anyway I can delete full set a set being the equivalent of locations[0] or locations[1] in the example below. I'd have to first iterate over the Object and try to figure out which one is which though. So lets say I am looking to remove an set where the zipcode is 06238, I would need to run over the entire locations object and find out which set it is in the object, then

Java- Save object data to a file [closed]

爱⌒轻易说出口 提交于 2020-01-21 03:40:48
问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 6 years ago . I've seen so many different posts about what way you're supposed to serialize an object to a file, and all of them conflict in nature on how to do it and what the best practices are. So here's what I'm trying to save: public class IHandler{ public double currentLoad; public String currentPrice;

Object.defineProperty or .prototype?

≯℡__Kan透↙ 提交于 2020-01-21 03:04:30
问题 I've seen two different techniques of implementing non-native features in javascript, First is: if (!String.prototype.startsWith) { Object.defineProperty(String.prototype, 'startsWith', { enumerable: false, configurable: false, writable: false, value: function(searchString, position) { position = position || 0; return this.lastIndexOf(searchString, position) === position; } }); } and Second is: String.prototype.startsWith = function(searchString, position) { position = position || 0; return

java学习笔记——内部类和Object根类

只愿长相守 提交于 2020-01-20 22:10:28
内部类和Object根类 文章目录 内部类和Object根类 内部类 普通内部类 内部类的特点 匿名内部类 Object Object概述 基本方法 内部类 内部类简单使用类内部的类就是内部类。 位置:把一个类定义到另一个类中,那么内部的类就是内部类。 注意:内部类不能直接创建 创建内部类的语法: 外部类.内部类 变量名 = new 外部类对象.new内部类对象 内部类的外部类的方法如果想要访问内部类的方法,必须创建内部类的对象,根据内部类的对象来访问。 普通内部类 class Outter { int num ; public void outMethod ( ) { System . out . println ( "我是外部的类的方法" ) ; } class Inner { int innerNum ; public void inMethod ( ) { System . out . println ( "我是内部的类的方法" ) ; } } } public class TestInner { public static void main ( String [ ] args ) { //创建内部类的对象 外部类.内部类 变量名 = new 外部类对象.new内部类对象 Outter . Inner inner = new Outter ( ) . new Inner

js判断两个对象是是否相等

孤者浪人 提交于 2020-01-20 21:12:31
用Object.is 只能判断两个对象应用的地址是不是一样 如果两个对象的应用地址不一样。两个对象对应的键和值是一样的,应用地址不一样。那么这时候判断两个对象用Object.is就行不通了 思路 需要递归每个键看看对应的值是否一样。 键对应的值有两种可能 是基本数据类型 (Number,String,Boolean,Null, undefined,symbol) 引用数据类型(Object,Array) 如果是基本数据类型 判断他们的值是否相等就行 如果是复杂数据类型 需要依次遍历他们的键看看值是否一致,当然前提键的数量是要一致的。 代码 const deepEqual = (obj1, obj2) => { const keys1 = Object.keys(obj1); const keys2 = Object.keys(obj2); return keys1.length === keys2.length ? keys1.every(key => { if (typeof (obj1[key]) === 'object') { return deepEqual(obj1[key], obj2[key]); } else { return obj1[key] === obj2[key]; } }) : false; } 例如下面两个对象 const obj1 = { name:

Object类

こ雲淡風輕ζ 提交于 2020-01-20 20:23:44
Object类是Java中所有类的根父类, Java中的类要么直接继承Object, 要么间接继承Object类 Java中类的继承是可传递的, Object类中定义的方法,所有的类都能继承到 Modifier and Type Method and Description protected Object clone() 对象克隆.很少使用 (在堆中创建一个一模一样的对象) boolean equals(Object obj) 用于判断两个对象的内容是否一样 protected void finalize() 当对象被垃圾回收器回收时,会执行 对象的finalize()方法.但是垃圾回收器在什么时候回收这个对象不确定, 即这个方法的执行时间不确定,一般不用 Class<?> getClass() 返回对象的运行时类对象, 可以简单的理解为返回对象的类的字节码文件 int hashCode() 返回对象的哈希码 void notify() 在线程中用于唤醒等待中的 线程 void notifyAll() String toString()把对象转换为字符串 toString() 作用是把对象转换为字符串 应用场景: System.out.println( obj ) 打印obj对象时, 会调用对象的toString()方法 ​ 当打印对象时,想显示对象的各个字段值,

使用不是有效变量名称的属性名进行对象解构

試著忘記壹切 提交于 2020-01-20 20:18:59
使用不是有效变量名称的属性名进行对象解构(Object destructuring with property names that are not valid variable names) JavaScript IT屋 2017/8/3 19:48:36 百度翻译此文 有道翻译此文 问 题 Does anyone know if you can use object destructuring with spaces in the property name? Maybe this cannot be done and I realize the JavaScript notation is incorrect but I cannot change the server json response. var obj1 = {name: ‘Mr Smith’, age: 21}; //destructure var {name, age} = obj1; //name=‘Mr Smith’ and age=21 This works as expected. But when I have the following object structure can I use object destructuring or not? var obj2 = {“my name”: