Advertisements Why my index.ts export const isNullOrUndefined = (value: any): value is null | undefined => { return value === null || value === undefined; }; is transpiled into index.d.ts (only value is null) export declare const isNullOrUndefined: (value: any) => value is null; instead of (value is null | undefined) export declare const isNullOrUndefined:… Read More Typescript: after the transpilation, wrong retun type
Advertisements Why my index.ts export const isNullOrUndefined = (value: any): value is null | undefined => { return value === null || value === undefined; }; is transpiled into index.d.ts (only value is null) export declare const isNullOrUndefined: (value: any) => value is null; instead of (value is null | undefined) export declare const isNullOrUndefined:… Read More Typescript: after the transpilation, wrong retun type
Advertisements I have a type: export type MyType = ‘something’ | ‘another’ | ‘else’; Then I would like to use just some of its options: Interface MyInterface { selection: Pick<MyType, ‘something’ | ‘another’> } But getting the error type doesn’t satisfy the constraint Is it not possible to use Pick on types but only on… Read More Typescript: pick from type not interface?
Advertisements I have a method that accepts argument of either string or MyEnum type and has a return type of only MyEnum. Also, there is a check – if a given argument is of MyEnum type, it will be returned immediately, otherwise additional logic is applied. But when I want to do that I get… Read More How to tell Typescript interpreter that variable will be a specific type in the runtime
Advertisements I have a parent component and a child component. I want to pass a function from parent component to child in onChange and also another function in the child component to update a state in the child component. How can this be done? Parent export function Fruits() { const onChangeHandler = (e: React.ChangeEvent<HTMLInputElement>) =>… Read More Passing 2 functions in onChange in react
Advertisements So here is my code from ts.Here i call the method updateProduct that makes a request to the API to update the product with the values that are in the form.The update is made but after i receive this error: error: SyntaxError: Unexpected token ‘P’, "Product Up"… is not valid JSON at JSON.parse (<anonymous>)… Read More After getting the API response my angular page is not redirecting to another page
Advertisements i have code: const Forms = () => { const [messageText, setMessageText]: any = useState(""); useEffect(() => { const getPosts = () => { axios.post(‘http://localhost:8080/graphql/’, { query: ` { getPosts(option: true) { id message } } ` }) .then((res) => { const andrey = res.data.data.getPosts setMessageText(andrey) }) .catch((error) => { console.error(error) }) }; getPosts()… Read More empty text when trying to iterate JSON from axios in react
Advertisements i want to pass information from parent to son, but i get error: Binding element ‘message’ implicitly has an ‘any’ type. What to do? Please help my code: const Forms = () => { const [messageText, setMessageText] = useState(""); useEffect(() => { API.getPosts() const handleMessage = () => { setMessageText("lox"); } }, []) return… Read More Binding element 'message' implicitly has an 'any' type
Advertisements I have below div in my HTML. <div row-index="0" /div> <div row-index="1" /div> I have to select specific div from above using its attribute. I am trying to do below in my typescript code. I get this index 0, 1 from another object. const value = event.rowIndex; –>line 1 const elem = document.querySelector(‘[row-index= value]’);… Read More Get HTML div element by its attribute and value using query selector API
Advertisements I have a typescript function with some params like that myFunction(allData: Array<any>, selectedItems: Array<any>, onlyValues: boolean = false, values: Array<any>) { console.log(allData); console.log(selectedData); console.log(onlyValues); console.log(values); } If onlyValues is set to true, I want values to be required, else, I don’t need values How to do this please >Solution : You could try with… Read More Typescript required param if other param = true