Returning a value from switch statement

I'm new to web development (JS) and I know there are many topics matching the title of mine, but no similar questions were answered, or maybe because I'm newbie, couldn't find.

In the code below I wanted my function and switch statements, to retrieve values from the arrays (bills) and in order to calculate new value, which to be assigned into a new non-existing place into the array tips. As a final result I want the function to return tips array with the value, depending on the case.

tips

tips

I know another way for solving this, anyway I was wondering whats wrong here, because that idea for solving it first came to my mind, and I thought it would work.

solving

Here is my code:

var tips = ;
var bills = [124, 48, 264];

function tipCalc(bills, tips)
switch(bills)
case bills < 50:
tips[0] = bills[1] * 0.2;
break;

case bills > 50:
tips[1] = bills[0] * 0.5;
break;

default:
console.log('no tips left.');

return tips;


tips = tipCalc(bills[0]);
console.log(tips);

enter code here


Array.push

return

switch

bills

bills < 50

bills > 50

tips

bills < 50

bills = (bills < 50)

3 Answers
3

Let's break this code down a bit and talk about what it's doing

var tips = ;
var bills = [124, 48, 264];


This part is declaring two variables in the global scope, which will both be accessible by any functions for both reading and writing (important - Google JS closures).

function tipCalc(bills, tips)
switch(bills)


You have now started a function which calls a switch to evaluate the value of bills. Because you are passing in bills[0], it will be evaluating bills[0] (124). It also accepts a second parameter called tips, which is undefined because no second argument is passed in when the function is called.

bills[0]

case bills < 50:
tips[0] = bills[1] * 0.2;
break;


This part is broken. If it was changed to an if statement, it would evaluate to false.

if

case bills > 50:
tips[1] = bills[0] * 0.5;
break;


Also broken. If changed to if statement, it would evaluate to true and be executed, but it would be performing an operation on undefined. If you didn't h have a second param also named tips, then you would be setting the global tips to 62.

if

tips

tips

default:
console.log('no tips left.');



This is the part that should currently be executed because it is the only one that can be true with the other two cases being structured incorrectly.

return tips;



Will return undefined because tips (within the scope of the function itself) began as undefined and has not been altered.

tips = tipCalc(bills[0]);
console.log(tips);
enter code here


Breaks the whole program, should be a comment with // at the beginning.

//

well, this is not good approach, but if it is required for you to use Switch you can try like this without bills array at all:

<script type="text/javascript">
var tips = ;



function tipCalc(bill)
switch (true)
case (bill < 50):
tips.push(bill * 0.2);
break;

case (bill > 50):

tips.push(bill * 0.5);
break;

default:
console.log('no tips left.');

return tips;


tipCalc(10);
for (let index = 0; index < tips.length; index++)
console.log(tips[index]);





</script>


Or in case you need to compare bills array and depends to the value insert to tips array i would make it like :

<script type="text/javascript">

var tips = ;
var bills = [124, 48, 264];

function tipCalc(bills)
for (let index = 0; index < bills.length; index++)

if (bills[index] <=50)
tips.push(bills[index] * 0.2);

else if (bills[index] >= 50)
tips.push(bills[index] * 0.5);

else
console.log("no tips left.");



tipCalc(bills);
for (let index = 0; index < tips.length; index++)
console.log(tips[index]);



</script>


else

<=50

>=50

Here's a verbose way of doing what I think you want to do. (add up the tips total)

// create a blank tips array which we'll add to later
var tips = ;
// our bills array
var bills = [124, 48, 264];
// create a function that will calculate tips based on the bill totals
function calculateTips()
// create a counter that we will use to determine when we've reached the end of the loop
var forEachCounter = 0;
// for each will loop through each item in the bills array
bills.forEach(function(amount)
//this increases the counter by 1 on each loop
forEachCounter++;
switch(true)
case (amount <= 50):
// .push appends to the array
tips.push(amount * 0.2);
break;
case (amount > 50):
// amount is the value of the bill for this iteration * 0.5
tips.push(amount * 0.5);
break;

// if end of array has been reached
// bills.length = the total amount of array items in bills arrat
if (forEachCounter === bills.length)
// create a totalTips variable to add to
var totalTips = 0;
// create another counter to detect when end is reached
var forEachCounter2 = 0;
// loop through the tips array
tips.forEach(function(tipamount)
// add 1 to counter on each loop
forEachCounter2++;
// add to totalTips
// can also do totalTips = totalTips + tipamount;
totalTips += tipamount;
// when end of tip array is reached..
if (forEachCounter2 === tips.length)
//alert(totalTips);
// output it to where you need it
document.getElementsByTagName('body')[0].innerHTML = totalTips;

)

)

// call it when you need it
calculateTips();

note

If you're working with a lot of tips (like an entire national restaurant chain) you may want to consider using if/else instead of switch because switch is demonstrated to be slower with ranges

fiddle with it here

https://jsfiddle.net/Hastig/p1kfgreq/

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