// TypeScript infers these variable types let personName = "Alice"; // inferred as string let age = 30; // inferred as number let isActive = true; // inferred as boolean let numbers = [1, 2, 3]; // inferred as number[] let mixed = [1, "two", true]; // inferred as (string | number | boolean)[] // Using the inferred types console.log(personName.toUpperCase()); // Works because personName is inferred as string console.log(age.toFixed(2)); // Works because age is inferred as number // personName.toFixed(2); // Error: Property 'toFixed' does not exist on type 'string' console.log(numbers); console.log(mixed);