How to handle nullable types in TypeScript

Short answer

TypeScript nullable types use union syntax like string | null or string | undefined. Use optional chaining (?.), nullish coalescing (??), and type guards to safely access values that might be null. For type narrowing techniques, see how to use TypeScript generics.

Common patterns

// Optional chaining
const name = user?.profile?.name;

// Nullish coalescing
const value = input ?? "default";

// Type guard
function processValue(val: string | null) {
  if (val !== null) {
    // TypeScript knows val is string here
    console.log(val.toUpperCase());
  }
}

Strict null checks

Enable strictNullChecks in tsconfig.json to prevent implicit any-to-null conversions. This catches most null-related bugs at compile time.

Tips

• Use ! (non-null assertion) only when you are certain the value exists
• Prefer explicit null checks over type assertions for safety