// Declare variables with types
    let message: string = "Hello, TypeScript!";
    let isCompleted: boolean = true;
    let total: number = 100;
    
    // Arrays
    let numbers: number[] = [1, 2, 3, 4, 5];
    let messages: Array<string> = ["Hello", "World"];
  
    // Tuples
    let tuple: [string, number];
    tuple = ["Hello", 10]; // Correct
    // tuple = [10, "Hello"]; // Error: Type 'number' is not assignable to type 'string'
  
    // Enum
    enum Color { Red, Green, Blue }
    let c: Color = Color.Green;
  
    // Any type
    let randomValue: any = 10;
    randomValue = "Hello";
    randomValue = true;
  
    // Unknown type
    let unknownValue: unknown = 10;
    unknownValue = "Hello";
    unknownValue = true;