Accelerator Track One

JavaScript Functions Drills

For this lab, you'll practice creating and using functions in JavaScript. You'll start with simple functions and gradually work up to more complex problems involving parameters, return values, and higher-order functions.

Instructions:

In functions.js, complete each prompt by writing a JavaScript function that satisfies the requirements. Make sure to invoke each function to run your code and verify it works as expected.

function example(){
    console.log('This function prints this message, but returns undefined')
}

example()

// => This function prints this message but returns undefined
// => undefined

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Functions Without Parameters

1. Basic Function
   Write a function named greet that prints "Hello, World!" to the console.

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Functions with Parameters

2. Single Parameter Function
   Write a function named greetPerson that takes in a name parameter and prints "Hello, [name]!" to the console.

3. Multiple String Parameters
   Write a function named introducePerson that takes in two parameters: name and occupation. It should print "Hi, my name is [name] and I am a [occupation]."

4. Number Parameter
   Write a function named doubleNum that takes in a number and returns its double.

5. Multiple Number Parameters
   Write a function named addNums that takes in two numbers and returns their sum.

6. Mixed Parameters
   Write a function named describePet that takes in three parameters: petName (string), species (string), and age (number). It should print "My pet [petName] is a [age]-year-old [species]."

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Functions Returning Values

7. Check Even or Odd
   Write a function named isEven that takes in a number and returns true if the number is even and false if the number is odd.

8. Calculate Area of a Rectangle
   Write a function named calculateArea that takes in two parameters: length and width, and returns the area of the rectangle.

9. Reverse a String
   Write a function named reverseString that takes in a string and returns the reversed version of the string.

10. Count Vowels in a String
    Write a function named countVowels that takes in a string and returns the number of vowels in the string.

11. Return Object from Mixed Parameters
    Write a function named createPet that takes in three parameters: petName (string), species (string), and age (number). It should return an object with the keys: 'name', 'species', 'age'.

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BONUS: Advanced Functionality

12. Function with Default Parameters
    Write a function named welcomeMessage that takes in a name parameter and prints "Welcome, [name]!" If no name is provided, the function should default to "Guest."

13. Function Calling Another Function
    Write a function named calculateAndLog that takes in two numbers, calls the addNumbers function to calculate their sum, and logs the result to the console.

14. Arrow Function
    Rewrite the doubleNumber function as an arrow function named doubleNum.

15. Higher-Order Function
    Write a function named applyFunction that takes in two parameters: a number and a callback function. It should apply the callback to the number and return the result.

    Example:

    const result = applyFunction(5, doubleNum);
    console.log(result); // Should print 10

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Submission Instructions:

• Complete all drills in the file functions.js.
• Test each function to ensure it works as expected.
• Push your completed work to your repository and submit the link on Google Classroom.
• Be prepared to explain how your code works during a follow-up discussion.

Good luck and happy coding! 🚀