数组表示有序数据的集合,对象表示无需数据的集合。如果数据顺序很重要的话,就用数组,否则就用对象的好。 数组的数据没有名称'name' 对象的数据有名称 'name' 但是在很多编程语言中有个叫关联数组的,这种数组中的数据是有名称的。 二、如何区分array和object: var obj = {"k1":"v1"}; var arr = [1,2]
ainstanceofArray// truetypeofa// "object"Array.isArray(a)// truevara=newArray()typeofa// "...
判断js 的 Array 和 Object vara = ['hello','world']; console.log(typeofa);//objectconsole.log(a.toString());//hello,word 字符串console.log(Object.prototype.toString.call(a));//[object Array]varb = {'hello':'world'}; console.log(typeofb);//objectconsole.log(b.toString());//[...
AI代码解释 packagetest.com.wanggs.com.wanggs.json.fastjson;importcom.alibaba.fastjson.JSON;importcom.alibaba.fastjson.JSONObject;importcom.alibaba.fastjson.serializer.SerializerFeature;importcom.wanggs.com.wanggs.json.fastjson.People;importorg.junit.Test;importstaticorg.junit.Assert.*;/** * Created by...
// 通过访问动态属性名 获取属性值'chen'Object.keys(obj) // 返回属性名集合 ['name', 'age']Object.assign(obj, { stature: 180, age: 20 }) // 后者对象的值和前者对象值合并覆盖 {name: "chen", age: 20, stature: 180} for (const key in obj) { console.log(key) } // 遍历对象 ...
Access array inside an object var b = { maths:[12,23,45], physics:[12,23,45], chemistry:[12,23,45] }; console.log(b.maths); // or console.log(b["maths"]); // and console.log(b.maths[0]); // first array item How to push an array into the object in JavaScript?
Add Items and Objects to an Array Using the push() Function in JavaScript To add items and objects to an array, you can use the push() function in JavaScript. The push() function adds an item or object at the end of an array. For example, let’s create an array with three values...
from()is not supported in Internet Explorer. JavaScript Array keys() TheArray.keys()method returns an Array Iterator object with the keys of an array. Example Create an Array Iterator object, containing the keys of the array: constfruits = ["Banana","Orange","Apple","Mango"]; ...
代码语言:javascript 代码运行次数:0 运行 AI代码解释 varmap=newMap();map.set('key1','value1');map.set('key2','value2');console.log(JSON.stringify(map));// {}functionstrMapToObj(strMap){letobj=Object.create(null);for(let[
从ECMAScript 2015 开始,Uint8Array构造函数需要通过new操作符调用。即日起如果没有使用new调用Uint8Array的构造函数,将会抛出TypeError。 js vardv=Uint8Array([1,2,3]);// TypeError: calling a builtin Uint8Array constructor// 不使用 new 将会被禁止 ...