4_FunctionsExercise.js

// Week 1 - Functions

// In the following exercises, you will need to place your code or answer underneath each exercise prompt.

// First try answering these without using references or looking up any information.
// Then, check your answer by using references and/or running your code.
// You can run your JS code using the Chrome or Firefox Developer tools, or by using Node.js.
// Feel free to update your answers if you got them wrong at first -- this exercise is for your own learning.
// But make sure you understand why the correct answer is right.

// Exercise 1. Define a function called logGreeting() that prints the string “Hello!” (use console.log).
// Underneath the function, write the line of code that runs the function.

function logGreeting(){
  console.log ("Hello!")
}
console.log(logGreeting())

// Exercise 2. Define a function called getName() that *returns* a string that is your name.
// Remember, this function should return the string -- not print it.
// Then print your name in the console by passing getName() into the console.log() function.
function getName(name){
  return name.toString()
}
console.log(getName("Peter"))
// Exercise 3. Call a function within a function -- Write a function called logGreeting2()
// that prints a full sentence that contains your name: "Hello! My name is <name>."
// logGreeting2 should call myName() to get your name.
// Then print your greeting to the console by calling logGreeting2().

function logGreeting2(){
  function myName(){
    let myName = "Mai"
    return myName
  }
  console.log (`Hello! My name is ${myName()}.`)
}

console.log(logGreeting2())

// Exercise 4. Write a function that takes 3 parameters that are all numbers.
// The function should return the sum of the 3 numbers.
// Then write some function calls you would use to test your function.

function exercise4(arg1, arg2, arg3){
  return arg1 + arg2 + arg3;
}

console.log(exercise4(3, 4, 5));
console.log(exercise4(5, -6, 9)); 
console.log(exercise4(5, 60, 88));


// Exercise 5. Let's say a museum gives a discount for children ages 14 or under, and seniors 65 or older.
// Write a function that takes in a person's age and returns true if they should get a discount.
// Otherwise it should return false.
// Then write some function calls you would use to test your function.

function exercise5 (age){
  if (age <= 14 || age >= 65) {
    return true; 
  } else {
    return false; 
  }
}

console.log(exercise5 (45)); 
console.log(exercise5 (66));
console.log(exercise5 (6));

// Exercise 6. Write a function that takes 2 parameters -- one number and one string.
// The function should print the string the given number of times.
// Then write some function calls you would use to test your function.

// Exercise 7. Read the following code (don't run it yet)
function mysteryFunction1(p1) {
  return p1 * 2;
}
const y = 4;
const z = mysteryFunction1(y);
console.log("The value of y is " + y);
console.log("The value of z is " + z);

// Without running the code, write down in a comment:
// 1. What mysteryFunction1 does? The function takes an integar and multiplies by 2; 
// 2. What prints out for the value of y? The value is 4;
// 3. What prints out for the value of z? The value is 8; 
// Now run the code and see if you're correct.
// Were you correct? If not, what did you learn? Yes. 
// Exercise 8. Read the following code (don't run it yet)
function mysteryFunction2(p1, p2) {
  const x = p1 - p2;
  return x;
}
const a = mysteryFunction2(10, 4);
const b = mysteryFunction2(a, 1);
console.log("The value of a is " + a);
console.log("The value of b is " + b);

// Without running the code, write down in a comment:
// 1. What mysteryFunction2 does? It takes two parameters (both integars) and substrate the first parameter over the second; and returns x which holds an integar; 
// 2. What prints out for the value of a? The value is 6;
// 3. What prints out for the value of b? The value is 5; 
// Now run the code and see if you're correct.Yes. 
// Were you correct? If not, what did you learn?

// Exercise 9. This exercise is to practice reading the documentation for functions.
// String.split() is a function in the JavaScript standard library that you can use in your code.
// Read about the split() function here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/split
// Try to use it to solve the following challenges:

// Here's a string I made representing my grocery list.
// Using split() and groceryList, make an array of my grocery list items

const groceryList = "eggs,carrots,orange juice";
newGroceryListArr = groceryList.split(",");
console.log(newGroceryListArr);

// Here's a string I made representing my morning schedule.
// Using split() and mySchedule, make an array of the *first 2* things I do in the morning
// There are multiple ways to do this, but try doing it using only the split() function.
const mySchedule = "wake up--->brush teeth--->eat breakfast--->go to work";
newMyScheduleArr = mySchedule.split("--->", 2);

console.log(newMyScheduleArr);
// Congrats, you made it to the end!
// Did you find this easy or hard? If you used references, which ones helped you?
// Please answer in a comment below.
//

// Email your file to the course staff,
// or commit your file to GitHub and email us a link.