PHP: Is there an alternative to using multiple if-statements?-CodePudding

I am in the making of some code that needs to check if a users login details are correct, and I therefore need a lot of if-statements inside each other. If any of the conditions in the if-statements are not true, they should alle return the same value. Is there an easy way of doing this, instead of writing the same multiple times? I have made an example below to visualize my problem. As you can see here I write " else { return false; }" multiple time, and this is what I am wondering if you are able to do more efficiently. Maybe so I only have to write "or else return false" once.

//some code
if (/*some condition*/) {
  //some code
  if (/*some new condition*/) {
    //some code
    if (/*some new condition*/) {
        //some code
      } else {
        return false;
      }
   } else {
     return false;
   }
} else {
  return false;
}

I am having a hard time finding a good way to explain my problem, so if you have a more elegant way of explaining it, do not hesitate to edit my post. I am also not quite sure that the title is as good as it could be, so if you have any ideas to an alternativ please say so :)

CodePudding user response：

Lets say you have something like that (I added No):

if ( condition1 ) {
  //some code 1
  if ( condition2 ) {
    //some code 2
    if ( condition3 ) {
        //some code 3
      } else {
        return false;
      }
   } else {
     return false;
   }
} else {
  return false;
}

Since each time a condition is false, you exit the function returning false, you can directly test if the condition is false using a negation (if the negated condition is true):

if ( !condition1 ) {
    return false;
}
//some code 1
if ( !condition2 ) {
    return false;
}
//some code 2
if ( !condition3 ) {
    return false;
}
//some code 3

This doesn't reduce the number of if statements, but you avoid many nesting levels and the else statements.

CodePudding user response：

You can also try the switch statement. For many situations it will produce cleaner code.

<?php
if ($i == 0) {
    echo "i equals 0";
} elseif ($i == 1) {
    echo "i equals 1";
} elseif ($i == 2) {
    echo "i equals 2";
}

switch ($i) {
    case 0:
        echo "i equals 0";
        break;
    case 1:
        echo "i equals 1";
        break;
    case 2:
        echo "i equals 2";
        break;
}
?>

The switch statement is also compatible with using strings:

<?php
switch ($i) {
    case "apple":
        echo "i is apple";
        break;
    case "bar":
        echo "i is bar";
        break;
    case "cake":
        echo "i is cake";
        break;
}
?>

Good luck! :)