I am trying to build a todo list app, and I am new to typescript. When the complete button is pressed on a task, I want it to be marked as completed. When I press the button the data has changed, but what is shown on the screen hasn’t changed. Here is the part in… Read More How to fix error "Argument of type 'void[]' is not assignable to parameter of type 'SetStateAction<ITask[]>'" in typescript react

I have a large application made with Angular 12 where in one part of it there is a parent component and a child component. Parent component (HTML): <app-sidenav></app-sidenav> <div class="row fadeIn animated"> <div class="col s12 m-0 p-2 pt-5"> <span class="card-title col s6 pt-4" style="font-size: x-large;"> {{‘Tasks’ | translate}} </span> <div class="col s6"> <app-filter [tasks]="tasks"></app-filter> </div>… Read More @Input() as undefined, even with @Input() data visible on the screen

I have a state in parent component which i want to update it from onClick in the child component, but it is not updating what is wrong here? Another Problem I want to show a popup when the user click in one of the radio button. And i have different popup messages for each radio… Read More Update the state in parent with onclick in CHild in React

I have a simple useState function that looks like this: const [value, setValue] = useState<values[]>([]); Theoretically, this will mean that the state of value defaults to an empty array. I then have a function that I’ve defined like this: function handleSelectValue(id: string) { let fakeArray:Array<values> = […Value, DefinedArray.find(x => x.id)] setValue(fakeArray); } I also tried:… Read More How to set a state variable to an empty array in React Typescript

I have a declaration like the following that works, but I feel like there is a simpler way to do it. function getData( slug: string | undefined = undefined ) { I would have thought this would work but it gives me syntax errors function getData( slug: string? = undefined ) { >Solution : What… Read More How to make passed in parameter optionally undefined in TypeScript

Assuming I have several functions that return the same number | Date type is it possible to define a type that will be one of these two? I.e. instead of: foo1(): number | Date {} foo2(): number | Date {} is it possible to have: foo1(): NumberOrDate {} foo2(): NumberOrDate {} ? Or is there… Read More Is it possible to define a type that resolves to one of two given types?

I have an object of objects that I’ve defined type aliases for and am trying to map through it but I’m stuck as how to handle the following error: Cannot invoke an object which is possibly ‘undefined’. Here is my use case: type apple = { color: string size: string } type apples = {… Read More How do I handle typescript nested objects being possibly undefined

I have an object of objects that I’ve defined type aliases for and am trying to map through it but I’m stuck as how to handle the following error: Cannot invoke an object which is possibly ‘undefined’. Here is my use case: type apple = { color: string size: string } type apples = {… Read More How do I handle typescript nested objects being possibly undefined

I have one array of objects, these objects have a timestamp attribute, I want to calculate the duration from the time stamp: myArray = [obj1, obj2, obj3]; ob1 = {"attr1":val1, "attr2":val2, "timestamp": …}; I want to get the duration between consecutive objects: (in python it would look a bit like this: durations = myArray[1:]-myArray[:-1]) >Solution… Read More How to get duration from array of objects with time stamps in typescript

Consider the following type for a column within a data table: interface Column<T> { key: keyof T; title: string; format?: (value: T[keyof T], record: T) => string | number; } T is the data type of the table records, and the value to be displayed in the column is indexed by the key property. A… Read More Is it possible to access the instanced value of an object property in a TypeScript interface