TypeScript keyof operatori
keyof - bu TypeScript-dagi kalit so‘z bo‘lib, u obyekt turidan kalit turini ajratib olish uchun ishlatiladi.
keyof aniq kalitlar bilan
Aniq kalitlarga ega obyekt turida foydalanilganda, keyof ushbu kalitlar bilan birlashma turini yaratadi.
Misol
interface Person {
name: string;
age: number;
}
// `keyof Person` here creates a union type of "name" and "age", other strings will not be allowed
function printPersonProperty(person: Person, property: keyof Person) {
console.log(`Printing person property ${property}: "${person[property]}"`);
}
let person = {
name: "Max",
age: 27
};
printPersonProperty(person, "name"); // Printing person property name: "Max"
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keyof indeks imzolari bilan
keyof indeks turini chiqarish uchun indeks imzolari bilan ham foydalanish mumkin.
Misol
type StringMap = { [key: string]: unknown };
// `keyof StringMap` resolves to `string` here
function createStringPair(property: keyof StringMap, value: string): StringMap {
return { [property]: value };
}
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