TypeScript · question
Question 9 of 99
What are readonly properties in TypeScript?
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Re-explain
Readonly properties can only be assigned during initialization and cannot be modified afterward:
interface Point {
readonly x: number;
readonly y: number;
}
const point: Point = { x: 10, y: 20 };
// point.x = 30; // Error: Cannot assign to 'x' because it is read-only
// Readonly arrays
const readonlyArray: readonly number[] = [1, 2, 3];
// readonlyArray.push(4); // Error: Property 'push' does not exist
// ReadonlyArray type
const numbers: ReadonlyArray<number> = [1, 2, 3];
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