Is there a more elegant way to execute this switch statement? - php

Question

I have a large switch statement in my code, and I want it to do something like this:
// assign $foo
switch ($foo) {
case 1:
case 2:
// do X, then break if 1, do Y and break if 2
case 3:
case 4:
case 5:
// do A & B, break if 3, do C if 4 or 5, do D if 5 and then break
}
Such "groups" are prevalent throughout the switch statement and currently I just repeat the logic, keeping each case separate.
Am I wrong in assuming that this could be restructured into something that's objectively "better"?
Edit: I excluded my original code snippet from the question, since it had deeply flawed logic and didn't conform to the basic concepts of using a switch, replacing it with pseudocode that resembles the desired result.

Answer 1

As commented, that switch doesn't actually work as you think.
You're simply looking for:
if (in_array($foo, [1, 2])) {
...
if ($foo == 2) {
...
}
}
Alternatively:
switch ($foo) {
case 1:
case 2:
...
if ($foo == 2) {
...
}
break;
}

Answer 2

TLDR;
For simple "is it this", use a switch, if you need logical checks, use an if
The answer;
What you are asking is quite subjective, while using a switch for something simple is good, i.e;
<?php
$case = getCaseFrom("X"); // Let's say this = "a"
switch ($case)
{
case "a" : {
$thing = "a";
break;
}
case "b" : {
$thing = "b";
break;
}
case "c" : {
$thing = "c";
break;
}
default : {
$thing = "d";
}
}
?>
The same could be achieved by using;
<?php
$case = getCaseFrom("x");
$thing = $case;
// And even shorter;
$thing = getCaseFrom("x");
?>
Whereas, if you needed some logic to this...
<?php
$operator = getOperatorFrom("X"); // In this case, add
$num1 = 10;
$num2 = 2;
switch ($operator)
{
case "add" : {
$res = num1 + num2;
break;
}
case "subtract" : {
$res = num1 - num2;
break;
}
case "multiply" : {
$res = num1 * num2;
break;
}
case "divide" : {
$res = num1 / num2;
break;
}
}
?>
The alternative;
And of course, all of the above switches case be done using if else clauses, but a switch (IMO) is a neater, and more readable approach depending on what your certain criteria are (see the drawbacks).
The easiest way to look at it is;
If you need to check if something matches a value, use an if, if it is an enumerated set of values (let's say 1 to 4), a switch is subjectively better
The drawbacks;
A switch also doesn't let you have multiple "and" checks in the same statement, for example;
<?php
$case = getCaseFrom("X"); // In this case, a (does not have "b")
switch ($case)
{
case "a" :
case "b" : {
// This checks for a or b, not both, despite this not containing "b"
// this will still be accessed
break;
}
case "c" : {
// This will not be used as the break stops
// it from falling through to this clause
break;
}
}
if (stristr("a", $case) && stristr("b", $case))
{
// This checks to see if case contains a AND b
// therefore, this will not be used, as this
// does not have both a and b in $case
}
else if (stristr("a", $case) || stristr("b", $case))
{
// This checks to see if case contains a OR b
// therefore, this will be used, as this
// is checking that $case has "a" or "b" in it
// This is the same as the switch in this instance as it uses "or"
}
The noteworthy;
To be aware of the following also would be useful;
Inside a switches case, you cannot use login, for example;
case getThing("a") :
would cause an error
NB: Of course, when using the case statements, you don't need the curly braces added, they are mainly for code folding and ease of reading