Category: TypeScript

Sometimes, we want to fix an enum type not defined at runtime with TypeScript.

In this article, we’ll look at how to fix an enum type not defined at runtime with TypeScript.

How to fix an enum type not defined at runtime with TypeScript?

To fix an enum type not defined at runtime with TypeScript, we can use the const or export keyword before the enum.

For instance, we write

const enum MyEnum {
  One = "one",
  Two = "two",
}

to create the MyEnum enum with the const keyword before it to keep it in the compiled JavaScript code as an object.

We can also write

export enum MyEnum {
  One = "one",
  Two = "two",
}

if we want to export the module and use it in another module.

Conclusion

To fix an enum type not defined at runtime with TypeScript, we can use the const or export keyword before the enum.

Sometimes, we want to create an object with a TypeScript interface as its type.

In this article, we’ll look at how to create an object with a TypeScript interface as its type.

How to create an object with a TypeScript interface as its type?

To create an object with a TypeScript interface as its type, we can use the as keyword to cast an object to the given type.

For instance, we write

const simpleObject = {} as ISimpleObject;

to cast the empty object to the ISimpleObject object type with as.

ISimpleObject is an interface with the list of properties with their types that can be in simpleObject.

Conclusion

To create an object with a TypeScript interface as its type, we can use the as keyword to cast an object to the given type.

Sometimes, we want to initialize a map containing arrays in TypeScript.

In this article, we’ll look at how to initialize a map containing arrays in TypeScript.

How to initialize a map containing arrays in TypeScript?

To initialize a map containing arrays in TypeScript, we can use the Map type.

For instance, we write

const map: Map<string, string[]> = new Map();

to create a Map instance with the Map<string, string[]> type.

The first type is the keys’ types and the 2nd type is the values’ types.

Conclusion

To initialize a map containing arrays in TypeScript, we can use the Map type.

Sometimes, we want to fix the "error TS2602: JSX element implicitly has type ‘any’ because the global type ‘JSX.Element’ does not exist" error with TypeScript.

In this article, we’ll look at how to fix the "error TS2602: JSX element implicitly has type ‘any’ because the global type ‘JSX.Element’ does not exist" error with TypeScript.

How to fix the "error TS2602: JSX element implicitly has type ‘any’ because the global type ‘JSX.Element’ does not exist" error with TypeScript?

To fix the "error TS2602: JSX element implicitly has type ‘any’ because the global type ‘JSX.Element’ does not exist" error with TypeScript, we can install the @types/react package to add the TypeScript type definitions for React.

To do this, we run

npm install --save-dev @types/react

to install it as a dev dependency.

Conclusion

To fix the "error TS2602: JSX element implicitly has type ‘any’ because the global type ‘JSX.Element’ does not exist" error with TypeScript, we can install the @types/react package to add the TypeScript type definitions for React.

To use namespaces with import in TypeScript, we can create ES6 modules and import them.

For instance, we write

UtilBase.ts

import * as path from "path";

export default class UtilBase {
  protected fixPath(value: string): string {
    return value.replace("/", path.sep);
  }
}

to export the UtilBase class as a default export.

Then we can import the module as a default import with

import UtilBase from "./UtilBase";
export default class UtilOne extends UtilBase {
  //...
}