如何检查多个变量并初始化非空变量？

I have a form with multiple inputs for one value which have similar names. something like this:

isset($_GET['name1'])
isset($_GET['name2'])
isset($_GET['name3'])

Always, either only one of them is true or none of them. And here is my code:

$name = '';
if( isset($_GET['name1']) ){
    $name = $_GET['name1'];
} else if ( isset($_GET['name2']) ) {
    $name = $_GET['name2'];
} else if ( isset($_GET['name3']) ) {
    $name = $_GET['name3'];
}

echo $name;

My code works as well. But I guess I can do that without those conditions. Any idea how can I write that logic more clean?

You can use a loop:

for ($i = 1; $i <= 3; $i++) {
    if (isset($_GET["name$i"])) {
        $name = $_GET["name$i"];
        break;
    }
}

Using the PHP 7 coalescing operator, you can write:

$name = $_GET["name1"] ?? $_GET["name2"] ?? $_GET["name3"] ?? "";

Here's an example how to do it that doesn't necessarily bind you to only the name name + 1 through 3. The order of preference goes from left (most preferable) to right (least preferable), where preferable refers to the order we pick them in.

$names=['name1','name2','name3'];

$name = '';
foreach ($names as $value) {
  if (isset($_GET[$value])) {
    $name = $_GET[$value];
    break;
  }
}
echo $name;

Loop through the GET array and test using empty

$name=false;
foreach( $_GET as $field => $value ){
    if( !empty( $value ) ) {
        $name=$value;
        break;
    }
}

Could possibly use the ternary operator for this like below.

$name = $_GET['name1'] ?: $_GET['name2'] ?: $_GET['name3'] ?: '';

which should skip name1 and go to name2 if name1 is empty or isn't set