How can I restructure `if` and `else` statements in PHP - php

Question

I have two (and sometimes) three variables which determine if I should run a specific code. The problem is that any of them can be true or false and sometimes this leads to messy codes.
For three variables, there are 8 possible scenarios that I have to check. Like this:
if($var_a && $var_b && $var_c) {
// Do this (A)
} else if(!$var_a && $var_b && $var_c) {
// Do this (B)
} else if($var_a && !$var_b && $var_c) {
// Do this (C)
} else if(!$var_a && !$var_b && $var_C) {
// Do this (D)
}
... and so on.
Is there any way to use nesting and make this code less messy? It gets confusing at times to keep track of so many possibilities.
It might be easier to understand what I am saying with an example of two variables.
if($var_a && $var_b) {
// Do this (A)
} else if($var_a && !$var_b) {
// Do this (B)
} else if(!$var_a && $var_b) {
// Do this (C)
}
Is there any way to combine these conditions together so that I don't have to use so many && and if else conditions? This will make things less confusing for me when I have to deal with three (may be more) variables.

Answer 1

I guess you should try something like lookup map with bitwise map, in your case, it can be something like this:
$bitOne = $var_a ? 1 : 0;
$bitTwo = $var_b ? 2 : 0;
$bitThree = $var_c ? 4 : 0;
$resultKey = $bitOne | $bitTwo | $bitThree;
$map = [
7 => function() { return 'All are true'; },
3 => function() { return 'var_a and var_b are true'; },
6 => function() { return 'var_b and var_c are true'; },
// and so on
];
$result = $map[$resultKey];

Answer 2

If you extract the common variable (or an arbitrary choice in this case), you can produce a more layered approach, although the combinations will still mount up and it looks more code, it should be clearer...
if($var_a) {
if(!$var_b) {
// $var_a && !$var_b
}
else {
// $var_a && $var_b
}
}
else {
if($var_b) {
// !$var_a && $var_b
}
}