JavaScript Road Trip Part 2 Level 2 Challenge 7

[mehulharia91]

Hey bijanbwb, thank you for helping me. I am sorry for causing you trouble by posting a new topic instead of adding it to this discussion.

[snychka]

Sorry for the late reply, and no huge problems!

The issue is that you had a space in your 2nd log before Removing.

Get rid of that, and everything will be correct. Cheers

[Tristan_Pease]

Here's my code:

 var numSheep = 4;
var monthsToPrint = 12;

for (var monthNumber = 1; monthNumber <= monthsToPrint; monthNumber++) {

  if(monthNumber%4==0&&numSheep<10000){
    console.log("Removing "+numSheep*0.75+" sheep from the population.");
    numSheep=numSheep*0.25;}   

  else if(numSheep>10000){
    console.log("Removing "+numSheep/2+" sheep from the population.");
    numSheep=numSheep/2;}

  numSheep *= 4;
  console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}

I didn't use a sheepToRemove var like the proposed solution above, but it doesn't seem to make a difference if I do.

The results I'm getting throw an error at
"There will be 16384 sheep after 7 month(s)!
Removing 8192 sheep from the population."

The error being "The first time there are more than 10000 sheep, you should log the message 'Removing 8192 sheep from the population.'"

What am I missing? It looks to me like my code meets that requirement... I'm not sure what to fix here. Help please!

[Tripol]

Hello Everyone,

Here's my code that keeps giving me an error message.

What am I doing wrong?

var numSheep = 4;
var monthsToPrint = 12;

for (var monthNumber = 1; monthNumber <= monthsToPrint; monthNumber++) {

if (monthNumber % 4 == 0){
var sheepPercentage = numSheep * .75;
console.log("Removing " + sheepPercentage + "sheep from the population");

numSheep *= 4;
console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}

[BrookeAH]

For the following code, I received an error message "Missing a semi-colon. Line 7".

var numSheep = 4;
var monthsToPrint = 12;

for (var monthNumber = 1; monthNumber <= monthsToPrint; monthNumber++) {

if(monthNumber % 4 === 0){
var sheepToRemove = .75 * numSheep;
console.log("Removing " + sheepToRemove + " sheep from the population.");
numSheep -= sheepToRemove;
} else if(numSheep > 10000) {
var sheepToRemove = numSheep / 2;
console.log("Removing " + sheepToRemove + " sheep from the population.");
numSheep -= sheepToRemove;
}

numSheep *= 4;
console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}

As you can see, there is clearly a semi-colon on line 7. The code passed when I changed the line to:

var sheepToRemove = numSheep * .75;

Does the order really matter in javaScript?
Is this a rule of javaScript: A variable must be first when defining a variable with another variable? (trying to find better wording.)

[BrookeAH]

Hi Tripol!
It looks like you created the variable sheepPercentage, and logged the message, but your code does not update the new amount of numSheep.

[snychka]

Hello. Logic's a bit off.

You must remove 75% each time numSheep is a multiple of 4. You're restricting it to being < 10000.

Nothing to do with sheepToRemove.

Here's the corrected code:

 var numSheep = 4;
var monthsToPrint = 12;

for (var monthNumber = 1; monthNumber <= monthsToPrint; monthNumber++) {

  if(monthNumber%4==0/*&&numSheep<10000*/){
    console.log("Removing "+numSheep*0.75+" sheep from the population.");
    numSheep=numSheep*0.25;}   

  else if(numSheep>10000){
    console.log("Removing "+numSheep/2+" sheep from the population.");
    numSheep=numSheep/2;}

  numSheep *= 4;
  console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}

[snychka]

Hey. It's a really odd issue, I think with jshint/lint, that doesn't like .75, and it gets confused a logs a misleading error.

You can change .75 to 0.75, and it'll work. Not sure if it's been logged as an issue, as it is tricky to fix properly, probably not quite worth it as it rarely happens, and working around it may cause more damage that good.

Cheers

[francisngo]

var numSheep = 4;
var monthsToPrint = 12;

for (var monthNumber = 1; monthNumber <= monthsToPrint; monthNumber++) {
    if (monthNumber % 4 === 0) {
      numSheep *= 0.75;
      console.log("Removing " + numSheep + " sheep from the population.");
    } else if (numSheep > 10000) {
      numSheep *= .5;
      console.log("Removing " + numSheep + " sheep from the population.");
    }
  numSheep *= 4;
  console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}

why doesnt this work? if var sheepRemoved = numSheep * 0.75 is the same as numSheep *= .75 ?

[snychka]

Hey. The issue is that you want to

• print out 75% of numSheep, and
• then remove 75% of numSheep.

numSheep *= 0.75; makes numSheep equal to 75%, but this is the amount to remove.

What you ended up doing was printing the right amount, but in essence only removing 25%.

sheepRemoved isn't required, but makes this solution way easier to understand.

[BrookeAH]

I meant to respond earlier... just wanted to say Thank you!

[Noxxys]

I initially had the following line:

if (monthNumber % 4 == 0) {

and I got the error "There was a problem running your code: Use '===' to compare with '0'."
And indeed, it works when using ===. Can anybody explain me why I would need this operator in that case? Thanks

[Gabe_Trejo]

argg.. I could not figure out why my submission was not accepted after printing out the correct numbers.. Then I realized I was missing a (.) at the end of the removal statement. Hate when that happens =/

---

moderator: coding is both love and hate. love and hate

[snychka]

Hey!

If things are done correctly, it would work either way.

In this case, it may help if monthNumber is a string. So, it may do some checking for you which is handy in a dynamically typed language.

Plus, === is quicker. A good habit to get into, using === and !==, although I don't think a primary focus of this or the following course.

[Noxxys]

Thanks! I'll use === for performance if types are the same

[xinkenan]

I made a mistake by forgetting to add a space in the string string concatenation. However, the error shows :" Incorrect Submission.The first time there are more than 10000 sheep, you should log the message 'Removing 8192 sheep from the population.'

Maybe this particular error checking logic could be improved to show correct error logic? It could help avoid confusion for new learners. = )

[snychka]

Hey!

That would be ideal, but is very tough. Attempts to do that in the original incarnations of the courses, glossed over many issues and resulted in false positives and negatives.

Best to avoid those, and come up with errors that are accurate, and based on output, not normally on the code itself.

Having said that, there may be a way to improve things, where it shows your output above the expected; same error, really, but would highlight differences a bit more easily. I did that in another challenge in a another course, and it worked great, so may do it here ... a bit tough to do, but possible.

Great that you figured things out, thanks for the suggestion, and the best solution at least for now is to come to this forum for help understanding error messages! Cheers

[danielsnewman1]

Hey everyone! I'm having some trouble understanding why my code isn't working in this challenge and I have pasted it below to see if I can get another set of eyes on it to see if I'm missing anything. What's even weirder about this is that it looks correct in the console, but it is still telling me that my code is incorrect. The number of sheep calculate from 16, to 64, to 256 for the first three months, but when the fourth month is inputed (monthNumber % 4 == 0), it reduces 256 to 192, which is right. Right? Can someone help e figure out whey I'm not getting this?

Thanks so much!

var numSheep = 4;
var monthsToPrint = 12;

for (var monthNumber = 1; monthNumber <= monthsToPrint; monthNumber++) {
  if(monthNumber % 4 == 0) {
    numSheep = numSheep * 0.75; 
    console.log("Removing " + numSheep + " sheep from the population.");
  } else if(numSheep >= 10000) {
    numSheep = numSheep / 2;
    console.log("Removing " + numSheep + " sheep from the population.");
  }
  numSheep *= 4;
  console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}

[melkir]

Where i'm i wrong ?

var numSheep = 4;
var monthsToPrint = 12;

for (var monthNumber = 1; monthNumber <= monthsToPrint; monthNumber++) {

  if(monthsToPrint%4 == 0){
    var sheepToRemove = numSheep * .75;
    console.log("Removing " + sheepToRemove + " sheep from the population.");
    numSheep -= sheepToRemove;
  }
  else if(numSheep > 10000) {
    var sheepToRemove = numSheep * .5;
    console.log("Removing " + sheepToRemove + " sheep from the population.");
    numSheep -= sheepToRemove;
  }

  numSheep *= 4;
  console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}

[snychka]

Hello Daniel! I tried yours out, and saw the message, so used that to determine that is was likely the first removal that was at issue.

Noticed you weren't removing 75%, but you were removing 25%. You need to print out 75%, and remove that amount, ending up with 25%.

Here's 1 fix:

var numSheep = 4;
var monthsToPrint = 12;

for (var monthNumber = 1; monthNumber <= monthsToPrint; monthNumber++) {
  if(monthNumber % 4 == 0) {
    var numSheepToRemove = numSheep * 0.75; 
    console.log("Removing " + numSheepToRemove + " sheep from the population.");
    numSheep -= numSheepToRemove;
  } else if(numSheep >= 10000) {
    numSheep = numSheep / 2;
    console.log("Removing " + numSheep + " sheep from the population.");
  }
  numSheep *= 4;
  console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}