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JavaScript

Posted by Dwayne Sauls
Dwayne Sauls
1,279 Points

Having trouble with variables

I do not understand the difference between these variables.Can somebody please elaborate for me?

var departmentName = ''; var highestSale = 0; var lowestSale;

3 Answers

Coen van Campenhout
Coen van Campenhout
5,034 Points
Coen van Campenhout
Coen van Campenhout
5,034 Points

Hi Dwayne,

do you have some context for the question? The ony answer I could give you right now is that

departmentName is an empty string as departmentName = "" indicates and highestSale is an integer

something that could also be giving you issues is the fact that yoy are not closing your quotes in departmentName try it like this: var departmentName = "";

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Hi Coen,

It was single quotes there so it's ok.

I agree that some context to the question would be helpful.

Dwayne Sauls
Dwayne Sauls
1,279 Points
Dwayne Sauls
Dwayne Sauls
1,279 Points

Hi Jason Anello Coen van Campenhout I have attached the following below: As an example one of the variables that has a value of zero I don't understand why.

////////////////////

var mostProfitableDay = function(database)
{
  var mondayTotalSales = 0;
  var tuesdayTotalSales = 0;
  var wednesdayTotalSales = 0;
  var thursdayTotalSales = 0;
  var fridayTotalSales = 0;

  for(var s = 0; s < database.length; s++)
  {
    if(database[s].day === 'Monday')
    {
      mondayTotalSales += database[s].sales;
    }

    if(database[s].day === 'Tuesday')
    {
      tuesdayTotalSales += database[s].sales;
    }

    if(database[s].day === 'Wednesday')
    {
      wednesdayTotalSales += database[s].sales;
    }

    if(database[s].day === 'Thursday')
    {
      thursdayTotalSales += database[s].sales;
    }

    if(database[s].day === 'Friday')
    {
      fridayTotalSales += database[s].sales;
    }
  }

  if(mondayTotalSales > (tuesdayTotalSales && wednesdayTotalSales && thursdayTotalSales && fridayTotalSales))
  {
    return "Monday was the most profitable day.";
  }

  else if(tuesdayTotalSales > (mondayTotalSales && wednesdayTotalSales && thursdayTotalSales && fridayTotalSales))
  {
    return "Tuesday was the most profitable day.";
  }

  else if(wednesdayTotalSales > (mondayTotalSales && tuesdayTotalSales && thursdayTotalSales && fridayTotalSales))
  {
    return "Wednesday was the most profitable day.";
  }

  else if(thursdayTotalSales > (mondayTotalSales && tuesdayTotalSales && wednesdayTotalSales && fridayTotalSales))
  {
    return "Thursday was the most profitable day.";
  }

  else
  {
    return "Friday was the most profitable day.";
  }

}

///////////////////

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

fixed code formatting

This link will show you how to post code: https://teamtreehouse.com/forum/posting-code-to-the-forum

Jason Anello
PLUS
Jason Anello
Courses Plus Student 94,610 Points
Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Hi Dwayne,

Those variables at the top are initialized to 0 because they're being used to calculate a total sum.

You start at zero and then you continually add more numbers to that giving you a total sum at the end.

This is a common pattern when you're calculating a running total. https://en.wikipedia.org/wiki/Running_total

Also, I don't think the logic in the last part is going to work the way you're intending. The logical AND comparsions are going to return the last sales value if all sales are greater than 0.

If there are any days where sales was 0 then the entire expression evaluates to 0.

This is going to lead to incorrect comparisons.

Let me know if you need help on going in a different direction there.