Don't understand this syntax found in calculator project

1

The handleClick method in( https://codepen.io/Snowd3n/pen/yqGaVm) starts:


handleClick = (buttonName) => {

switch(true){

case buttonName === "0" ||  etc.

I’m familiar so far with methods that start:

handleClick(event)
{
do x, y and z
}

It looks like the handleClick method is taking the value of ‘buttonName’ from the button that’s been clicked, and using it in a subsequent method which contains a select case statement.

Also, I don’t understand why switch has an argument set to true: switch(true).

Basically, this code syntax is unfamiliar to me. Could anyone explain or provide a link to an explanation. Thank you.

3

Looking at that codepen, it seems like a perfect example of how NOT to write a calculator app. It’s using the switch statement in a strange way, and the code is really repetitive and not structured very well (no offense to whoever wrote it). It’s not a good example to learn from.
Normally you would use switch case like:


switch (buttonName){
case "0": 
       do something
break
case "1": 
       do something else
break
}

where each case would handle a different value of buttonName, but in this case, the case statements are each handling several values at once, which is not normally how cases are used.