我有下一节课
public class OracleStoredProcedures
{
public static readonly string GET_ALL_PRODUCTS_BY_ID = $"{PRODUCT_PACKAGE_NAME}.GET_ALL_PRODUCTS_BY_ID";
public static readonly string GET_LATEST_PRODUCTS = $"{PRODUCT_PACKAGE_NAME}.GET_LATEST_PRODUCTS";
public static readon
我正在继续一个前同事的项目,我对一些代码有疑问,我不明白其中的某些部分。
为了给您提供一些上下文,我们有一个UserInfo类,它看起来如下:
export class UserInfo {
constructor(
public readonly userLoginId: string,
public readonly hasLocalPassword: boolean,
public readonly loginMethods: Array<LoginInfo>,
public readonly loginMethodsAvailable:
如果我想定义一个元组或常量对象形状,我会使用as const。例如: const arr = [{ a: 1 }] as const;
/* readonly [{
readonly a: 1;
}] */ 然而,我不想要readonly,因为我会得到很多The type 'readonly ...' is 'readonly' and cannot be assigned to the mutable type '...' 我定义了一个“可变”泛型: type Mutable<T> = {
-readonly [K in
我经常遇到这个问题():
const arr = [1,2,3] as const
const doSomethingWithNumbers = <T extends number[]>(numbers: T) => {}
doSomethingWithNumbers(arr)
// ^
// Argument of type 'readonly [1, 2, 3]' is not assignable to parameter of type 'number[]'.
// The type
new Map([[1, [2, 3]] ].map(e => e[1]));是完全有效的javascript。但是,类型记录会出现以下错误:
No overload matches this call.
Overload 1 of 3, '(iterable: Iterable<readonly [unknown, unknown]>): Map<unknown, unknown>', gave the following error.
Argument of type '(number | number[])[]'
这是Infer shape of result of Object.fromEntries() in TypeScript的延续,尽管您可能不需要阅读它就能知道发生了什么。 我正在尝试扩展Array原型,以便在Object.fromEntries()周围添加一个快捷方式,前提是数组的形状适合它。 // the aforementioned question uses this signature for Object.fromEntries() replacing `this`
// with a parameter `array`
interface Array<T> {
我以以下方式实现了一个TypeScript枚举:
export class Size{
static SMALL = new Size('smaller than 100', 1, 100);
static MEDIUM = new Size('smaller than 1000', 1, 1000);
readonly description: string;
readonly from: number;
readonly to: number;
private constructor(description
抱歉,标题不好,我不知道如何用一句话更好地解释它。
我只会粘贴到目前为止的代码,因为我相信它应该是很清楚的。
// I have a columns const that never changes
const columns = ["a", "b", "c"] as const
// I have editable columns, that is a subset of columns,
// which also never changes, so I make it readonly.
type EditableColumns = re
下面的代码片段抛出了一个类型错误。我希望label的类型是'a' | 'b',但它是string。
export const obj = {
a: 1,
b: 2
} as const
const label = Math.random().toString(32)
if (label in obj) {
const p = obj[label];
console.log(p)
}
Element implicitly has an `any` type because expression of type `string` cannot b