{Object.keys(raptors).map(key=>( <likey={key}>{raptors[key].name}</li> ))} </ul> ); } Mapping Values The second approach usesObject.values, which when passed an object will return you an array containing the values of the object. ...
Iterators Now you can iterate over iterable objects (including arrays, array-like objects, and iterators), invoking a custom iteration hook with statements to be executed for the value of each distinct property. For more information, see Iterators and Generators. Note: Generators are not yet suppo...
};vardecaf =function(){this.name='decaf';this.basePrice=6; };// create object literals for the different sizesvarsmall = {getPrice:function(){returnthis.basePrice+2},getLabel:function(){returnthis.name+' small'} };varmedium = {getPrice:function(){returnthis.basePrice+4},getLabel:functi...
//映射对象集合到特定的属性名称的生成器。function*iteratePropertyValues(collection, property) {for(letobjectofcollection) {yieldobject[property]; } }//生成给定对象的每个值的生成器。function*iterateObjectValues(collection) {for(letkeyofObject.keys(collection)) {yieldcollection[key]; } }//生成给定数组...
An iterable can be iterated over with the code:for (const x of iterable) { } Example // Create an Object myNumbers = {}; // Make it Iterable myNumbers[Symbol.iterator] =function() { letn =0; done =false; return{ next() { ...
Create an Array Iterator, and then iterate over the key/value pairs: constfruits = ["Banana","Orange","Apple","Mango"]; constf = fruits.entries(); for(letx of f) { document.getElementById("demo").innerHTML+= x; } Try it Yourself » ...
Object.getOwnPropertySymbols(programmingLanguage.__proto__); /** end of how to check if type/object implements the Symbol.iterator */ 如您所见,上面的代码示例显示String数据类型确实实现了@@iterator。因此,Strings是可迭代的。 内置的迭代器看起来怎么样?
But in the case of a generator that returns a value, the final call tonextreturns an object that has bothvalueanddonedefined. Thevalueproperty holds the return value of the generator function and thedoneproperty istrueindicating that there are no more values to iterate. This final value is ...
Object.fromEntries() String.prototype.{trimStart,trimEnd} Symbol.prototype.description JSON improvements Well-formed JSON.stringify() Function.prototype.toString() ECMAScript 简介 每当阅读 JavaScript 相关的文章时,我都会经常遇到如下术语: ES3, ES5, ES6, ES7, ES8, ES2015, ES2016, ES2017, ECMAScript...
Use Object.keys() and Array.prototype.reduce() to iterate over each key with an appropriate initial value. Use Boolean to determine the truthiness of each key's value and add it to the accumulator if it's truthy. Use typeof to determine if a given value is an object and call the func...