PHP switch case more than 1 value in the case

问题:

I have another situation. I have a variable that holds the values ('Weekly', 'Monthly', 'Quarterly', 'Annual'), and I have another variable that holds the values from 1 to 10.

switch ($var2) {
       case 1:
          $var3 = 'Weekly';
          break;
       case 2:
          $var3 = 'Weekly';
          break;
       case 3:
          $var3 = 'Monthly';
          break;
       case 4:
          $var3 = 'Quarterly';
          break;
       case 5:
          $var3 = 'Quarterly';
          break;
       // etc.
}

It isn't beautiful, because my code has a lot of duplicates. What I want:

switch ($var2) {
       case 1, 2:
          $var3 = 'Weekly';
          break;
       case 3:
          $var3 = 'Monthly';
          break;
       case 4, 5:
          $var3 = 'Quarterly';
          break;
}

How can I do it in PHP? Thank you in advance. Sorry for my english.

回答1:

the simplest and probably best way performance wise would be:

switch ($var2) {
       case 1:
       case 2:
          $var3 = 'Weekly';
          break;
       case 3:
          $var3 = 'Monthly';
          break;
       case 4:
       case 5:
          $var3 = 'Quarterly';
          break;
}

also, possibile for more complex situations:

switch ($var2) {
    case ($var2 == 1 || $var2 == 2):
        $var3 = 'Weekly';
        break;
    case 3:
        $var3 = 'Monthly';
        break;
    case ($var2 == 4 || $var2 == 5):
        $var3 = 'Quarterly';
        break;
}

in this scenario, $var2 must be set and can not be null or 0

回答2:

switch ($var2) {
       case 1 :
       case 2 :
          $var3 = 'Weekly';
          break;
       case 3 :
          $var3 = 'Monthly';
          break;
       case 4 :
       case 5 :
          $var3 = 'Quarterly';
          break;
}

Everything after the first matching case will be executed until a break statement is found. So it just falls through to the next case, which allows you to "group" cases.

回答3:

Switch is also very handy for AB testing. Here the code for randomly testing 4 different versions of something:

$abctest = mt_rand(1, 1000);
switch ($abctest) {
   case ($abctest < 250):
     echo "A code here";
     break;
   case ($abctest < 500):
     echo "B code here";
     break;
   case ($abctest < 750):
     echo "C code here";
     break;
   default:
     echo "D code here";
     break;