How to format switch/case?

#1

finalGrade()

when I try to run the code below for switch, it fails (goes for the undefined) however when I try the same logic for if when comparing if the number is in-between two other numbers, it works. Is there logic behind this? otherwise I understand that only way to understand if a number is in-between 2 other numbers is if/else if statement but not switch. I prefer switch because it’s easier to read and read since everything is under one curly braces.

const finalGrade = (n1,n2,n3)=>{
  let average = (n1+n2+n3)/3
  console.log(average);
  return showLetterGrade(average);
}

const showLetterGrade = gpa => {
 /* switch (gpa){
    case (gpa>0 && gpa<=59):
      return "F";
      break;
  }*/
  if (gpa>0 && gpa<=59){
    return 'F';
  }
}
console.log(finalGrade(40, 42, 45))
#2

The logic is simple… When the switch parameter matches the case, that branch is followed.

switch(boolean):
case boolean:

switch(number)
case number:

switch(string)
case string:

gpa is a value (a number). Are there any cases that match this?

This is a contradiction of terms. You do understand what GPA means?

#3

A switch normally only has one boolean check per case statement.

This person had the same type of problem.

The above link has 2 different ways to solve this.

#4

You need to check the boolean of the case vs a boolean of the switch(expr).
Just change it to switch(true) then run… also make sure the default sentence has a (.) otherwise it will still show as not solved.

#5

is there a way that you can make that you can add (as a argument) as many grades as you want? and if yes, then how do you make that the average should automatically divide according to how many grades you’ve entered?

#6

arguments and arguments.length.

#7

oh, so you make /arguments.length! but how do you add? i dont understand what i am suppose to do with the arguments

#8

Sum of an array? Nothing special there.
I generally prefer to represent things in data rather than code - so I’d use a single argument, an array.

#9

Is there a simpler way to check if multiple variables are within a certain numerical range? image

FAQ: Code Challenges: JavaScript Fundamentals - finalGrade()
#10

There are other ways, but given the number of variables and conditions it’s doubtful any of them will be simpler. Take this bit of silliness, for example:

 > grade1 = -1, grade2 = 101, grade3 = -10
 > switch(true) {
     case 0 > grade1:
     case 0 > grade2:
     case 0 > grade3:
     case grade1 > 100:
     case grade2 > 100:
     case grade3 > 100:
       console.log('Invalid grade');
       break;
     default: console.log((grade1 + grade2 + grade3) / 3);
   }
<- Invalid grade

 > grade1 = 1, grade2 = 100, grade3 = 10
 > switch(true) {
     case 0 > grade1:
     case 0 > grade2:
     case 0 > grade3:
     case grade1 > 100:
     case grade2 > 100:
     case grade3 > 100:
       console.log('Invalid grade');
       break;
     default: console.log((grade1 + grade2 + grade3) / 3);
   }
<- 37
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#11

Thanks for that :+1:, I was trying with a switch statement before but then I realised that I was comparing a number (grade) to a conditional (0 > grade1) so it wouldn’t work.

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