Javascript detect values one-by-one from an object 1 2 3 4 5 6 7 8 let obj = { name: "Porter", age: 32 }; for (const key of Object.keys(obj)) { const val = obj[key]; console.log(val); } Run > Reset To use ECMAScript 2015 fat-arrow functions and to map the object ...
console.log(Object.keys(obj)); 输出如下: Object.getOwnProperty 用于返回对象的自有属性,包括可枚举和不可枚举的 var obj = {"name":"Poly", "career":"it"} Object.defineProperty(obj, "age", {value:"forever 18", enumerable:false}); Object.prototype.protoPer1 = function(){console.log("proto...
与Object.getOwnPropertyNames() 类似,你可以将给定对象的所有符号属性作为 Symbol 数组获取。请注意,Object.getOwnPropertyNames() 本身不包含对象的 Symbol 属性,只包含字符串属性。 因为所有的对象在初始化的时候不会包含任何自有的 Symbol 属性,除非你在对象上分配了 Symbol 属性,否则 Object.getOwnPropertySymbols() ...
Object.getOwnPropertyDescriptor() 静态方法返回一个对象,该对象描述给定对象上特定属性(即直接存在于对象上而不在对象的原型链中的属性)的配置。返回的对象是可变的,但对其进行更改不会影响原始属性的配置。
//可以看到单个属性的描述符 console.log(Object.getOwnPropertyDescriptor(data, 'Lima')) // {value: "58/40", writable: false, enumerable: false, configurable: true} 获取所有属性里面的数据描述符 —— Object.getOwnPropertyDescriptors() 只接受一个参数,目标对象。 // 可以看到所有属性里面的数据描述...
Example 1: JavaScript Object.getOwnPropertyDescriptors() let obj = { x: 10, get number() { return this.x; }, }; // get the property descriptors for all the properties of obj let value = Object.getOwnPropertyDescriptors(obj); console.log(value); Run Code Output { x: { value: ...
For that purpose, you should use the object.keys method to get access to all the keys of object.Then you can use indexing like Object.keys(objectName)[0] to get the key of first element:Javascript Object.keys method1 2 3 4 5 let obj = { valueName: 'someVal' }; let val = obj...
constkey=Symbol('key')exportclassA{[key]=1value(){console.log(this[key])}} It seems thatkeyis not expose to outside of module, but still we are able to get it. import{A}from'./module.js'consta=newA()constkeys=Object.getOwnPropertySymbols(a)console.log(keys)//[Sybmol(key)]const...
System.Runtime.InteropServices.JavaScript.dll Returnstypeof()of the property. C# publicstringGetTypeOfProperty(stringpropertyName); Parameters propertyName String The name of the property. Returns String One of "undefined", "object", "boolean", "number", "bigint", "string", "symbol" or "f...
constuser={name:'Alex',age:30}constprops=Object.getOwnPropertyNames(user)console.log(props)// [ 'name', 'age' ] If you are interested in the own enumerable properties of the object, use theObject.keys()method instead: constuser={name:'Alex',age:30}constprops=Object.keys(user)console.log...