// Here we are defing an array const fruits: string[] = ["apple", "banana", "orange"]; // Here we will check if // the array contains "apple" const hasApple: boolean = fruits.includes("apple"); // Here we will
"dom","dom.iterable","scripthost"], // 指定我们需要用到的库,也可以不配置,直接根据 target 来获取 /* Specify a set of bundled library declaration files that describe the target runtime environment. */"jsx":"preserve",// jsx 的处理方式(保留原有的jsx格式)"module":"commonjs",// ...
private 和 protected。 public: 默认的修饰符,它表示属性或方法是公有的,可以在类的内部和外部被访问。 private: 表示属性或方法是私有的,只能在类的内部被访问,外部无法访问。 protected: 表示属性或方法是受保护的,只能在类的内部及其子类中被访问,外部无法访问。 1.private 修饰符 示例: classPerson{privatenam...
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Array<VNode>;text: string | void;elm: Node | void;ns: string | void;context: Component | void; // rendered in this component's scopekey: string | number | void;componentOptions: VNodeComponentOptions | void;componentInstance: Component | void; // component instanceparent: VNode | void; ...
Use the find() Method to Check if a String Is Present in a TypeScript ArrayThe find() method returns the first occurrence of the target element if it successfully executes, or else it returns undefined.var fruitsArray : string[] = ['apple', 'orange', 'lichi', 'banana']; if(fruitsAr...
//点击5次移出事件 let i:number = 1; let btn = document.querySelector('#btn') as HTMLButtonElement; function oneclick(event:MouseEvent) { document.title =''+i; if(i>=5) btn.removeEventListener('click',oneclick); console.log('第'+i+'次点击'); i++; } btn.addEventListener('click...
我们发现在checkSourceFileWorker函数内有各种各样的check操作,先执行了checkGrammarSourceFile进行语法检查,后面执行checkSourceElement、checkDeferredNodes等才对具体的节点进行具体的语义检查。其中其实也是做了一个分发,根据node.kind来判断节点的类别,执行不同类型节点的检查函数。 function checkSourceElementWorker(node:...
//ClassTag用法 def mapProductIterator[B: ClassTag](f: Any => B): Array[B] = {// protected def mapProductIterator[B: ClassTag](f: Any => B): Array[B] = { val arr = Array.ofDim[B](productArity) var i = 0 while (i < arr.length) { arr(i) = f(productElement(i)) i +=...
let element = event as unknown as HTMLElement; // Okay! } 慎用as any和as unknown 通常情况是类型断言S和T的话,S为T的子类型,或者T为S的子类型,这种是相对安全的。 假如是用as any或者as unknown,是非常不安全的。慎用!慎用! // 谨慎使用 ...