js constarray=Array.from(document.querySelectorAll("[id]")).map((e)=>e.id);constset=newSet(array);console.assert(set.size===array.length); 规范 Specification ECMAScript® 2026 Language Specification #sec-set-objects 浏览器兼容性
There is one important thing to note about using an Object or Array as a key: the Map is using the reference to the Object to compare equality, not the literal value of the Object. In JavaScript{} === {}returnsfalse, because the two Objects are not the same two Objects, despite havi...
js的Map的API可以查看 https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Map const mps =newMap(); mps.set('name', 'brian') .set('job', 'banker') .set('age', 30); console.log(mps.get('job'));for(const [key, val] of mps) { console.log(key, val...
代码语言:javascript 代码运行次数:0 运行 AI代码解释 funmain(){// 创建可变列表集合varmutableList=mutableListOf("Tom","Jerry")// 添加元素mutableList.add("Jack")// 删除元素mutableList.remove("Tom")println(mutableList)// 将 可变列表集合 转为 只读列表集合val list:List<String>=mutableList.toList()/...
Observe and intercept operations on arbitrary JavaScript objects and arrays using a utility-first, general-purpose reactivity API! This API re-explores the unique design of theObject.observe()API and takes a stab at what could bea unifying APIoverrelated but disparatethings likeObject.observe(),Ref...
Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, Python, PHP, Bootstrap, Java, XML and more.
The last one will simply print out the same array we provided when we made an instance of the Map. Well, it is an array that has arrays as elements. Map vs Object You are probably wondering why would we use Map if we can simply use JavaScript’s objects. They are also very similar...
Objects have the ability to use data and methods that other objects contain, as long as it lives on the [[prototype]] chain. In this lesson we’ll test this out by adding properties and working with this linkage of properties. Objects in JavaScript give us the ability to create key and...
Introduction to Set object in JavaScript五月16, 2019 In this article 👇 Creating a new Set object Set methods Adding objects in Set Iterating over a Set object Keys and values ConclusionA Set is a new type of object in ES6 that lets you create a collection of unique values. Each ...
代码语言:javascript 代码运行次数:0 运行 AI代码解释 NSArray *array2 = [set allObjects]; (二)NSMutableSet 1、可变集合初始化 代码语言:javascript 代码运行次数:0 运行 AI代码解释 NSMutableSet *mSet1 = [NSMutableSet setWithObjects:@"1", @“2”, @“3”, @“4”, nil]; //可变集合初始化 NSMut...