:string):string{ if(lastName){ return fristName + lastName; }else{ return fristName; } } //传一个参数调用 let bob = buildName('bob'); console.log(bob); //传两个参数调用 let zhangsan = buildName('zhang','san'); console.log(zhangsan); 剩余参数,指参数在自定义时无法确定需要上送...
function getVersion(version:string) { if (!version) { version = "1.0.0"; } return version; } console.log(getVersion("1.0.1")); 使用常见配置选项 { "compilerOptions": { "target": "ES6", // 目标语言的版本 "removeComments": true, // 删除注释 "outDir": "./dist/", // 编译输出路...
functiongetUrls(url: string | URL, names: string[]){if(typeofurl==="string") {url=newURL(url); }returnnames.map(name => {url.searchParams.set("name", name)// ~~~// error!// Property 'searchParams' does not exist on type 'string | URL'.returnurl.toString(); }); } Here, ...
constfullNameMaxLength=10;classEmployee{private_fullName:string="";getfullName():string{returnthis._fullName;}setfullName(newName:string){if(newName&&newName.length>fullNameMaxLength){thrownewError("fullName has a max length of "+fullNameMaxLength);}this._fullName=newName;}}letemployee=newEmp...
If the only known fact about the type is that it's some object, use the type object, not Object or { [key: string]: any }. var foo: string | any: When any is used in a union type, the resulting type is still any. So, while the string portion of this type annotation may ...
if (typeof foo === "string") { // 这里 foo 被收窄为 string 类型 } else if (typeof foo === "number") { // 这里 foo 被收窄为 number 类型 } else { // foo 在这里是 never const check: never = foo; } } 注意在 else 分支里面,我们把收窄为 never 的 foo 赋值给一个显示声明的...
TypeScript 包含各种基本类型，例如 Number、Array、Tuple、Boolean、String 等等。好吧，其中一些类型在 ...
string().base64(); Check out validator.js for a bunch of other useful string validation functions that can be used in conjunction with Refinements. You can customize some common error messages when creating a string schema. const name = z.string({ required_error: "Name is required", ...
number//因为我们在下边有具体函数的实现,所以这里并不需要添加 declare 关键字//下边是实现function add (arg1:string| number, arg2:string|number) {//在实现上我们要注意严格判断两个参数的类型是否相等,而不能简单的写一个 arg1 + arg2if(typeofarg1 ==='string'&&typeofarg2 ==='string') {returnar...
}elseif(typeofnickname ==='number') {console.log(`你的昵称是number类型${nickname}`) }else{thrownewError('请检查类型') } }checkNickname('赤蓝紫')checkNickname(123)checkNickname(true) 从上面的例子中,可以看到checkNickname只是接受string和number类型,当我们传boolean类型的时候,会在编译期间报错。