Code Typing · TypeScript
Type Guard
Validate unknown values with a predicate.
Difficulty: Intermediate · 15 Lines · License: public-domain
type User = {
id: number;
name: string;
email: string;
};
function isUser(value: unknown): value is User {
if (!value || typeof value !== 'object') return false;
const v = value as Record<string, unknown>;
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