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...
//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...
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.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...
keys()is not supported in Internet Explorer. JavaScript Array entries() Example Create an Array Iterator, and then iterate over the key/value pairs: constfruits = ["Banana","Orange","Apple","Mango"]; constf = fruits.entries(); for(letx of f) { ...
77. Iterate Over Object Properties Write a JavaScript program to iterate over all the properties of an object, running a callback for each one. Click me to see the solution 78. Invert Key-Value Pairs in Object Write a JavaScript program to invert the key-value pairs of an object, without...
function* iterateObjectValues(collection) { for (let key of Object.keys(collection)) { yield collection[key]; } } //生成给定数组中每个项的生成器。 function* iterateArrayElements(collection) { for (let element of collection) { yield element; } } 这些函数简洁小巧,易于使用。麻烦的是这些函数...
The `listDocumentModels` method will only // iterate over model summaries, which do not include detailed schema information. Schema information is only returned // from `getDocumentModel` as part of the full model information. const models = client.listDocumentModels(); let i = 1; for await...
to iterate over arrays, and Object.keys() / Object.values() / Object.entries() to produce arrays so you can iterate over objects. const numbers = [1, 2, 3, 4, 5]; // bad let sum = 0; for (let num of numbers) { sum += num; } sum === 15; // good let sum = 0; ...
Iterate over array elements or object key-value pairs. Returning false from the iterator function stops the iteration. $.each(['a', 'b', 'c'], function(index, item){ console.log('item %d is: %s', index, item) }) var hash = { name: 'zepto.js', size: 'micro' } $.each(hash...