3_LoopsExercise.js

// Week 2 - Loops

// 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. Write a 'while' loop that prints the integers (whole numbers)
// between 1 and 5 (inclusive).
 
function exercise1 (){
  let i = 1; 
  while (i <= 5){
    console.log(i)
    i++;
}

// Exercise 2. Write a 'do while' loop that prints the integers (whole numbers)
// between 1 and 5 (inclusive).
function exercise2(){
  let i = 1;
  do {
    console.log(i);
    i++; 
  }
  while (i <=5);
}
// Exercise 3. Write a 'for' loop that prints the integers (whole numbers)
// between 1 and 5 (inclusive).
function exercise3(){
  for (let i = 1; i <=5; i++){
    console.log(i)
  }
}
// Exercise 4. Now we want a loop that prints the integers
// counting DOWN from 10 to 1 (inclusive). Write three loops that do this, to practice
// writing loops in all 3 ways -- as a 'while', 'do while', and 'for' loop.
function exercise4While (){
  let i = 10; 
  
  while (i > 0){
    console.log(i)
    i--;
  }
}

function exercise4While_1 (){
  let i = 10; 
  do {
    console.log(i)
    i--;
  } while (i > 0);
}

function exercise4For(){
  for (let i = 10; i >0; i--){
    console.log(i)
  }
}

// Exercise 5. Write a loop that prints the integers from 7 to 27. Write this
// loop in all 3 ways -- as a 'while', 'do while', and 'for' loop.
function exercise5(){
  let i = 7; 
  while (i <= 27){
    console.log(i)
    i++;
}
}

function exercise5DoWhile(){
  let i = 7; 
  do {
    console.log(i);
    i++
  } while (i<=27);
}
  
function exercise5For(){
  for (let i = 7; i<=27; i++){
    console.log(i)
  }
}
// Exercise 6. Write a loop that prints numbers between 0 and 100, counting by tens.
// I.e. it will print 10, then 20, then 30, etc.
// Write this loop in all 3 ways -- as a 'while', 'do while', and 'for' loop.

function exercise6While (){
  let i = 10; 
  while (i < 100){
  console.log (i); 
  i = i + 10;
  }
}

function exercise6DoWhile (){
  let i = 10; 
  do {
    console.log (i);
    i = i + 10
  } while (i < 100); 
}

function exercise6For (){
  for (let i = 10; i < 100; i = i + 10){
    console.log(i);
  }
}

// Exercise 7. Add a comment as to why the following loop is an infinite loop (will run without ever stopping). Then fix the loop so that it stops when counterFour is equal to -100.

function exercise7 (){
  let counterFour = 1;
  while (counterFour >= -100) {
    console.log("HELP ME!");
    console.log(counterFour)
    counterFour--;
  }
}

// Exercise 8. Make a variable that contains your favorite integer. Write a loop
// (your choice which type) that prints the integers from 0 to that number.

function myFav (){
  let favVar = 13; 
  for (let i = 0 ; i <= favVar; i++){
    console.log (i); 
  }
}

// Exercise 9. Make a variable that contains your favorite integer (this time make sure it's
// less than 100). Write a loop (your choice which type) that prints the integers from 0 to 100.
// Next to each number it should print "not my favorite number". But next to your favorite
// number it should print "my favorite number!". Example output (if your favorite number was 2):
// 0 not my favorite number
// 1 not my favorite number
// 2 my favorite number!
// 3 not my favorite number
// ...
// (Hint - use an if statement in your loop)

function exercise9 (){
  let myfav = 13; 
  for (i = 0; i <= 100; i++){
    if (i != myfav){
      console.log (i + " not my favorite number")
    } else if (i === myfav){
      console.log ("my favorite number!")
    }
  }
}

// Exercise 10. In some of the exercises above, we had you write all 3 types of loops, for practice.
// But in real life, how would you decide which type of loop to use? You might not have an  exact answer, but spend a few minutes thinking about the different types of loops and/or doing some research and write down your thoughts in a comment below:
// I think for personal preference, I find the for-loop to be the most elegant one and is my main preferance but that could change with more experience. 


// Exercise 11. Now we'll practice using nested loops (a loop inside another loop)!
// Update the nested loops below to so that for each value of outsideCounter,
// the inside loop will show a countdown

/*
counting down from 0
*********************************** 
counting down from 1
inside 1
*********************************** 
counting down from 2
inside 2
inside 1
*********************************** 
counting down from 3
inside 3
inside 2
inside 1
*********************************** 
*/

for (let outsideCounter = 0; outsideCounter <= 3; outsideCounter++) {
  console.log("counting down from", outsideCounter);
  for (let insideCounter = outsideCounter; insideCounter > 0; insideCounter--) {
     console.log("inside " + insideCounter)
  }
  console.log("***********************************");
}

// 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 us or commit your file to GitHub and email us a link.