Question

I have this code where $difference=0

switch ($difference) 
{
case 0<=$difference && $difference<300:
         return "A";
    break;
case 300<=$difference && $difference<600:
        return "B";
    break;  
}

I think that switch must return A but it returs B. Whats wrong ???

Answer 1

I’m posting this merely as informative.

Switches can be used with expressions, however this is tricky to do:

<?php
$value = 300;
$other = 1;

switch (true) {
    case $value <= 300 && $other:
        $var = 'A';
        break;

    case $value >= 300 && !$other:
        $var = 'B';
        break;

    case $value >= 300 && $other:
        $var = 'C';
        break;

    case $value > 300 && $other:
        $var = 'D';
        break;

    default:
        $var = 'FALSE';
        break;
}

echo $var;

The above code will display ‘C’ correctly. A combination of if/else statements is equivalent but I tend to find the switch more readable. Be sure to always include a default case whose value you can rely on (or maybe return from the function, throw an exception, etc).

You can also compare other variables, types, call functions (although not recommended), etc to match the value declared in the switch statement (in this case, true but can be an integer, string or any other base type).