indexOf() 方法查找字符串 a 在 arr数组中的位置(索引) const arr = ['a','b']; console.log(arr.indexOf('a')); // 0 1. 2. 3. 检查数组是否包含某个元素 includes()方法存在则返回true,反之为false。 indexOf()方法测试索引值不是 -1。 如果indexOf()不返回-1,则数
slots.includes(column.dataIndex as string)">{{ parseDefaultValue(record as T, column.dataIndex as string) }}</span> </template> </Table> </template> <!-- 这里定义泛型 T 并且使用 BaseData 约束 --> <script lang="ts" setup generic="T extends BaseData = BaseData"> const slotObjects =...
A DisposableStack is an object that has several methods for keeping track of Disposable objects, and can be given functions for doing arbitrary clean-up work. We can also assign them to using variables because — get this — they’re also Disposable! So here’s how we could’ve written ...
This includes things like changing file extensions, changingpathslookups to their resolutions, changing absolute paths to relative paths, changing relative paths to absolute paths, changing sub-module specifiers to something else, and so on. The string in the import path is the string in the emitte...
function sum(nums: number[]): number: UseReadonlyArrayif a function does not write to its parameters. interface Foo { new(): Foo; }: This defines a type of objects that are new-able. You probably wantdeclare class Foo { constructor(); }. ...
The TypeScript compiler includes several settings which affect core aspects of the language. Configure TypeScript usingtsconfig.jsonrather than command-line options. Turn onnoImplicitAnyunless you are transitioning a JavaScript project toTypeScript. ...
Function signature includes the following.The data type of the parameterfunction disp(string):void; function disp(number):void; The number of parametersfunction disp(n1:number):void; function disp(x:number,y:number):void; The sequence of parameters...
The Record<Keys, Type> is a utility type in TypeScript that helps define objects with specific key-value pairs. It creates an object type where the property keys are of type Keys, and the values are of type Type. This is particularly useful when you need to ensure that an object has ...
String-based enums, just like object literals, support computed names with the use of the square bracket notation, and this is usually not the case for number-based enums. Therefore, this limits our ability to use number-based enums in JSON objects, as it is usually not possible to compu...
objects.all() def post(self, request, *args, **kwargs): username = request.data.get('username', '') password = request.data.get('password', '') user = authenticate(username=username, password=password) if user is not None and user.is_active: login(request, user) serializer = User...