How to handle a PHP switch with different types?

Question

How can I make the switch respect data types ( is there a workaround better then if/else ) ?

$value = false; // should echo false

$value = null; // should echo null

switch ($value) {
    case '0' :
        echo 'zero';
        break;
    case '' :
        echo 'empty';
        break;
    case null :
        echo 'null';
        break;
    case false :
        echo 'false';
        break;
    default :
        echo 'default';
        break;
}

Conclusion

Switch/case does loose comparison.

Solutions: switch with ifs or if/else

Answer 1

switch (true) {
    case $value === '0' :
        echo 'zero';
        break;
    case $value === '' :
        echo 'empty';
        break;
    case $value === null :
        echo 'null';
        break;
    case $value === false :
        echo 'false';
        break;
    default :
        echo 'default';
        break;
}

I think, it's more readable than a if-elseif-chain like given below:

if ($value === '0') {
  echo 'zero';
} else if ($value === '') {
  echo 'empty';
} else if ($value === null) {
  echo 'null';
} else if ($value === false) {
  echo 'false';
} else {
  echo 'default';
}

Answer 2

i believe you can try if-then to facilitate the use of '===' instead:

<?php
$value = 0;

if ($value==="") {
  echo "blank (string)";
}
else
if ($value==="0") {
  echo "zero (string)";
}
else
if ($value===false) {
  echo "false (boolean)";
}
else
if ($value===null) {
  echo "null (object)";
}
else
if ($value===0) {
  echo "zero (number)";
}
else {
  echo "other";
}
?>

Answer 3

in php.net manual it is a

note: Note that switch/case does loose comparision.

"loose comparison" means that switch won't check the type. 
 switch will only compare values:

---

<?php 
if('a string' == 0) echo 'a string is 0' . PHP_EOL;
if('a string' === 0) echo 'but you will never see this' . PHP_EOL;
switch(0){
    case 'a string': echo 'a string' . PHP_EOL;
    case 'another string': echo 'another string' . PHP_EOL;
}

if('a string' == true) echo 'a string is TRUE' . PHP_EOL;
if('a string' === true) echo 'but you will never see this' . PHP_EOL;
switch(true){
    case 'a string': echo 'a string' . PHP_EOL;
    case 'another string': echo 'another string' . PHP_EOL;
}
?>

will output:
a string is 0
a string
another string
a string is TRUE
a string
another string

Answer 4

another option, depending on what you like to look at:

switch($foo ?: strtoupper(gettype($foo))){
    case 'bar':
    case 'bork':
        echo $foo;
        break;

    case 'NULL': // $foo === null
        echo 'null';
        break;

    case 'INTEGER': // $foo === 0
        echo 'zero';
        break;

    case 'ARRAY': // $foo === array()
        echo 'array';
        break;

    case 'STRING': // $foo === ''
        echo 'empty';
        break;

    case 'BOOLEAN': // $foo === false
        echo 'false';
        break;

    default:
        echo $foo;
        break;
}

depending on your data, you could include an underscore for added clarity, like '_NULL', but it's not as clean IMO.

personally, I concur with the accepted answer for something like a quick null check:

case $foo === null:

Answer 5

Bare in mind that you're asking PHP to juggle types.

If you see the PHP type comparison table you'll see that, for example, null and '' are loosly equivalent, ie null == ''.