Learn JavaScript from Scratch JavaScript for Everyone - Functions: Reusing Code

The video tutorial introduces functions in JavaScript, emphasizing the DRY principle for code reuse. It covers creating functions, using external JavaScript files, and provides examples like a greeting function. The tutorial explains typecasting, handling data types, and understanding function types and return values. It concludes with a homework assignment to practice creating functions with parameters.

What is the main benefit of using functions in programming?

• They are only useful for mathematical operations.

• They help in reusing code and following the DRY principle.

• They make it harder to debug code.

• They make code longer and more complex.

What is the purpose of the 'return' statement in a function?

• To declare a new variable.

• To output a value from the function.

• To stop the function from executing.

• To call another function.

What happens if you try to access a variable declared with 'const' inside a function, from outside the function?

• The variable is automatically converted to a global variable.

• The variable is duplicated outside the function.

• An error occurs because the variable is out of scope.

• The variable can be accessed without any issues.

How can you ensure that a function always treats its parameters as numbers?

• By using the 'string' method.

• By using typecasting to convert parameters to numbers.

• By using the 'boolean' method.

• By declaring parameters as 'const'.

What is the result of executing a function without parentheses?

• The function is executed immediately.

• The function is treated as a string.

• The function returns 'undefined'.

• The function is treated as a reference.

What does the 'typeof' operator return when used on a function?

• It returns 'object'.

• It returns 'undefined'.

• It returns 'function'.

• It returns 'number'.

What is the purpose of the exercise at the end of the lesson?

• To practice creating a function that multiplies two numbers.

• To practice creating a function that adds two numbers.

• To practice creating a function that divides two numbers.

• To practice creating a function that subtracts two numbers.