const p2: User<boolean> = { gender: true } 这样看起来, 泛型是不是非常方便呢。同样, 也可以设置一个, 也可以设置多个 // 制作一个方法的接口泛型 interface Search { <T, Y>(name: T,age: Y): T } let fn:Search = function <T, Y>(name: T, id: Y): T { // ... 此处省略代码 1...
}constclones = cloneArray(heros); When we check the 'clones' type, you can see it is 'any[]'. To add more type information we can change the function: function cloneArray<T>(ary: T[]): T[] {returnary.slice(0); } Now we get 'clones' type as 'HasName[]'. Generic Class: c...
function firstElement1<Type>(arr: Type[]) { return arr[0]; } function firstElement2<Type extends any[]>(arr: Type) { return arr[0]; } // a: number (good) const a = firstElement1([1, 2, 3]); // b: any (bad) const b = firstElement2([1, 2, 3]); 乍一看,两种方法似...
When we check the 'clones' type, you can see it is 'any[]'. To add more type information we can change the function: function cloneArray<T>(ary: T[]): T[] {returnary.slice(0); } 1. 2. 3. Now we get 'clones' type as 'HasName[]'. Generic Class: classSuperCharacter { co...
functionfunctionName<T>(param1:T,param2:T):T{// Function body} ‘<T>’: Specifies the type parameter. ‘param1’, ‘param2’: Parameters of type T. ‘: T’: Specifies the return type. 1.2. Generic Function Example In the following example, we have anadd()function that can accept ...
function combine<Type>(arr1: Type[], arr2: Type[]): Type[] { return arr1.concat(arr2); } 编译错误: 解决办法:使用尖括号语法,显式传入类型参数:这里 T = string | number,意思是接收 string 或者 number 类型均可。 编写generic 函数的最佳实践 ...
expression, we can use the “infer” keyword to either get the type of the elements of an array, or even to get the return type of a function. We can use this to build a “FnReturnType” type, that will give us the return type of the function passed in as the generic parameter....
# 泛型函数 (Generic Functions)我们经常需要写这种函数,即函数的输出类型依赖函数的输入类型,或者两个输入的类型以某种形式相互关联。让我们考虑这样一个函数,它返回数组的第一个元素:function firstElement(arr: any[]) { return arr[0]; } 注意此时函数返回值的类型是 any,如果能返回第一个元素的具体类型就...
expression, we can use the “infer” keyword to either get the type of the elements of an array, or even to get the return type of a function. We can use this to build a “FnReturnType” type, that will give us the return type of the function passed in as the generic parameter....
function generic<T>() {} interface Generic<T> {} class Generic<T> {} 2. 初识泛型之所以使用泛型,是因为它帮助我们为不同类型的输入,复用相同的代码。比如写一个最简单的函数,这个函数会返回任何传入它的值。如果传入的是 number 类型:function identity(arg: number): number { return arg } ...