我想我应该对上面的一些回复进行扩展....

class nameCheck{

public $name;

public function __construct(){
    $this->name = $name;
}

function firstName(){
            // If a name has been entered..
    if(!empty($this->name)){
        $name = $this->name;
        $errflag = false;
                    // Return a array with both the name and errflag
        return array($name, $errflag);
            // If its empty..
    }else if(empty($this->name)){
        $errmsg = 'Please enter a name.';
        $errflag = true;
                    // Return both the Error message and Flag
        return array($errmsg, $errflag);
    }
}

}


if($_POST['submit']){

$a = new nameCheck;
$a->name = $_POST['name'];
//  Assign a list of variables from the firstName function
list($name, $err) = $a->firstName();

// Display the values..
echo 'Name: ' . $name;
echo 'Errflag: ' . $err;
}

?>
<form method="post" action="<?php $_SERVER['PHP_SELF']; ?>" >
<input name="name"  />
<input type="submit" name="submit" value="submit" />
</form>

这将为您提供一个输入字段和提交按钮，一旦提交，如果名称输入字段为空，它将返回错误标志和一条消息。如果name字段有值，它将返回值/name，如果false =无错误，则返回错误标志0。 希望这能有所帮助!

允许多次返回的语言通常只是将多个值转换为一个数据结构。

例如，在Python中，您可以返回多个值。但是，它们实际上只是作为一个元组返回。

你可以在PHP中返回多个值只需创建一个简单数组并返回。

这是最简单的方法:

public function selectAllUsersByRole($userRole, $selector) {

    $this->userRole = $userLevel;
    $this->selector = $selector;

    $sql = "SELECT * FROM users WHERE role <= ? AND del_stat = 0";
    $stm = $this->connect()->prepare($sql); // Connect function in Dbh connect to database file
    $stm->execute([$this->userRole]); // This is PHP 7. Use array($this->userRole) for PHP 5

    $usersIdArray = array();
    $usersFNameArray = array();
    $usersLNameArray = array();

    if($stm->rowCount()) {
        while($row = $stm->fetch()) {

            array_push($usersIdArray,    $row['id']);
            array_push($usersFNameArray, $row['f_name']);
            array_push($usersLNameArray, $row['l_name']);

            // You can return only $row['id'] or f_name or ...
            // I used the array because it's most used.
        }
    }
    if($this->selector == 1) {
        return $usersIdArray;
    }elseif($this->selector == 2) {
        return $usersFNameArray;
    }elseif($this->selector == 3) {
        return $usersLNameArray;
    }

}

我们如何调用这个函数呢?

$idData = $selectAllUsers->selectAllUsersByLevel($userRole, 0);
print_r($idData);
$idFName = $selectAllUsers->selectAllUsersByLevel($userRole, 1);
print_r($idFname);

就是这样。非常容易。

可以从一个函数返回多个数组和标量

function x()
{
    $a=array("a","b","c");
    $b=array("e","f");
    return array('x',$a,$b);
}

list ($m,$n,$o)=x();

echo $m."\n";
print_r($n);
print_r($o);

它不可能有两个返回语句。然而，它不会抛出错误，但当函数被调用时，你只会收到第一个返回语句值。 我们可以使用return of array来获取多个返回值。例如:

function test($testvar)
{
  // do something
  //just assigning a string for example, we can assign any operation result
  $var1 = "result1";
  $var2 = "result2";
  return array('value1' => $var1, 'value2' => $var2);
}

没有办法返回两个变量。虽然，你可以传播一个数组并返回它;创建一个条件返回一个动态变量，等等。

例如，这个函数将返回$var2

function wtf($blahblah = true) {
    $var1 = "ONe";
    $var2 = "tWo";

    if($blahblah === true) {
      return $var2;
    }
    return $var1;
}

在应用程序:

echo wtf();
//would echo: tWo
echo wtf("not true, this is false");
//would echo: ONe

如果你两个都想要，你可以稍微修改一下函数

function wtf($blahblah = true) {
    $var1 = "ONe";
    $var2 = "tWo";

    if($blahblah === true) {
      return $var2;
    }

    if($blahblah == "both") {
      return array($var1, $var2);
    }

    return $var1;
}

echo wtf("both")[0]
//would echo: ONe
echo wtf("both")[1]
//would echo: tWo

list($first, $second) = wtf("both")
// value of $first would be $var1, value of $second would be $var2