如何压缩if语句代码？

So I have a variable named bestmatchrule which returns a single number between 1-25 and now Im trying to assign that number a name using the following if statement:

$a=$bestmatchrule;
$b='';

if ($a == "1" || "2") {
      $b="Chesil House";
} elseif ($a == "3" || "4") {
      $b="Corfe House";
} elseif ($a == "5" || "6") {
      $b="Cranborne House";
} elseif ($a == "7" || "8") {
        $b="Dorchester House";
} elseif ($a == "9" || "10") {
      $b="Lyme Regis House";
} elseif ($a == "11" || "12") {
      $b="Okeford House";
} elseif ($a == "13" || "14") {
      $b="Purbeck House";
} elseif ($a == "15" || "16") {
      $b="Student Village";
} elseif ($a == "17" || "18" || "19") {
      $b="Unilet";
} elseif ($a == "20") {
      $b="Conel Court";
} elseif ($a == "21" || "22") {
      $b="St John's Road";
} elseif ($a == "23" || "24" || "25") {
      $b="Private Let";
} else {
     "Please Try Again";
}

Problem is it doesn't work. It only returns the top one. Is this an issue with the value returned or the if statement?

Also, if there a way of shortening it to make it look nicer? I'm more focused on functionality, but there has to be a better way than this?

Thanks in advance! (p.s. sorry for the noob question!)

$a == "1" || "2" is not a valid statement. It would need to be $a == "1" || "$a == 2". That's your error.

As far as shortening this, there isn't much you can do. You can use in_array() to shorten some statements but you don't really have any where that would be truly handy.

if ($a == "1" || $a == "2") {
      $b="Chesil House";
} elseif ($a == "3" || $a == "4") {
      $b="Corfe House";
} elseif ($a == "5" || $a == "6") {
      $b="Cranborne House";
} elseif ($a == "7" || $a == "8") {
        $b="Dorchester House";
} elseif ($a == "9" || $a == "10") {
      $b="Lyme Regis House";
} elseif ($a == "11" || $a == "12") {
      $b="Okeford House";
} elseif ($a == "13" || $a == "14") {
      $b="Purbeck House";
} elseif ($a == "15" || $a == "16") {
      $b="Student Village";
} elseif (in_array($a, array("17", "18","19")) {
      $b="Unilet";
} elseif ($a == "20") {
      $b="Conel Court";
} elseif ($a == "21" || $a == "22") {
      $b="St John's Road";
} elseif (in_array($a, array("23", "24", "25")) {
      $b="Private Let";
} else {
     echo "Please Try Again";
}

You can also use an array to hold your values wit the $a value being the key. Then just check to see if it is in the array and if so, assign the value:

$array = [
    1 => "Chesil House",
    2 => "Chesil House",
    3 => "Corfe House",
    4 => "Corfe House",
    5 => "Cranborne House",
    6 => "Cranborne House",
    7 => "Dorchester House",
    8 => "Dorchester House",
    9 => "Lyme Regis House",
    10 => "Lyme Regis House",
    11 => "Okeford House",
    12 => "Okeford House",
    13 => "Purbeck House",
    14 => "Purbeck House",
    15 => "Student Village",
    16 => "Student Village",
    17 => "Unilet",
    18 => "Unilet",
    19 => "Unilet",
    20 => "Conel Court",
    21 => "St John's Road",
    22 => "St John's Road",
    23 => "Private Let",
    24 => "Private Let",
    25 => "Private Let"
];

if (isset($array[$a])) {
    $b = $array[$a];
}
else {
    echo "Please Try Again";
}

John Conde's answer is probably what you want. One other possibility is progressive less than (<) statements.

$a= (int) $bestmatchrule;
$b='';

if ($a < 3) {
      $b="Chesil House";
} elseif ($a < 5) {
      $b="Corfe House";
} elseif ($a < 7) {
      $b="Cranborne House";
} elseif ($a < 9) {
        $b="Dorchester House";
} elseif ($a < 11) {
      $b="Lyme Regis House";
} elseif ($a < 13) {
      $b="Okeford House";
} elseif ($a < 15) {
      $b="Purbeck House";
} elseif ($a < 17) {
      $b="Student Village";
} elseif ($a < 20) {
      $b="Unilet";
} elseif ($a < 21) {
      $b="Conel Court";
} elseif ($a < 23) {
      $b="St John's Road";
} elseif ($a < 26) {
      $b="Private Let";
} else {
     "Please Try Again";
}

A switch statement is also an option, but I don't think it would be much better.