//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...
Object.entries() Object.getOwnPropertyDescriptors() 尾逗号 共享内存 and 原子操作 ES2018 Rest/Spread Properties Asynchronous iteration Promise.prototype.finally() 正则表达式改进 ESNext Array.prototype.{flat,flatMap} try/catch 可选的参数绑定 Object.fromEntries() String.prototype.{trimStart,trimEnd} Symb...
};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...
迭代Map let recipeMap = new Map([['cucumber', 500],['tomatoes', 350],['onion', 50]]);// iterate over keys (vegetables)for (let vegetable of recipeMap.keys()) {alert(vegetable); // cucumber, tomatoes, onion}// iterate over values (amounts)for (let amount of recipeMap.values())...
val.filter(Boolean):val;// Reduce the object to a compacted version, removing falsy values recursivelyreturnObject.keys(data).reduce((acc,key)=>{constvalue=data[key];// Check if the value is truthy before including it in the resultif(Boolean(value))// Recursively compact object values, if...
Thesome()method checks if some array values pass a test. This example checks if some array values are larger than 18: Example constnumbers = [45,4,9,16,25]; letsomeOver18 = numbers.some(myFunction); functionmyFunction(value, index, array) { ...
Theiterator protocoldefines how to produce asequence of valuesfrom an object. An object becomes aniteratorwhen it implements anext()method. Thenext()method must return an object with two properties: value (the next value) done (true or false) ...
即在Object.values上迭代)，那么迭代[...numbers.values()]，这实际上相当于映射。空间成本是相似的-...
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 ...
function*iterateObjectValues(collection){for(letkeyofObject.keys(collection)){yieldcollection[key];}}//生成给定数组中每个项的生成器。function*iterateArrayElements(collection){for(letelementofcollection){yieldelement;}} 这些函数简洁小巧,易于使用。麻烦的是这些函数中的每一个都会对传入的集合做出判断。它是...