将PHP 5.4升级到PHP 7.4后未返回正确的值。-PHP中文网问答

我正在尝试将在PHP 5.4上运行的某些脚本在PHP 7.4上运行。除了已经修复的过时的传引用错误之外，没有检测到语法错误。

在应用程序的某个部分，我没有得到正确的返回值。我运行了php7cc和PHPStorm来查看是否可以捕捉到任何错误和过时警告，但没有任何能够解决问题的线索。

有一个脚本解析XML数据并将其放入一个类对象中。_MV_WRITE_._MV_SEP_._MV_SEP_.$this->mvKey._MV_SEP_.$this->mvObj->toString()._MV_SEP_这一部分都是正确的，除了$item->toString()返回的是空白而不是正确的字符串值。

在这些代码中是否有任何在PHP 5.4中有效但在PHP 7.4中无效的内容？以下是有问题的代码。

主要脚本


    
        Demo MV
    
    
";

echo "Creating XML Parser. 
";
$xp = New XMLParser();

echo  "Parsing XML to MV item. 
";
If( !$xp->ParseToMVItem( $xmltext ) ) {
    echo "Parsing XML item failed. 
";
}

echo  "Getting formatted output. 
";
$item = $xp->GetMVItem();
echo print_r( $item ) . "
";

$fv = New MVFile("123456789", $item);
$mvObject = $fv->getFormattedItem( );
echo "Formatted output: " . $mvObject . "
";
    
?>

XML Parser

MVItem = New MVItem("");

        // create parser
        $this->xp = xml_parser_create();
        xml_set_object( $this->xp, $this );

        // set element handlers
        xml_set_element_handler($this->xp, "elementBegin", "elementEnd");
        xml_set_character_data_handler($this->xp, "characterData");
        xml_parser_set_option($this->xp, XML_OPTION_CASE_FOLDING, FALSE);

        // parse data
        if (!xml_parse($this->xp, $xml, True )) 
        {
            $errstring = " Line: " . xml_get_current_line_number( $this->xp);
            $errstring .= " Column: " . xml_get_current_column_number( $this->xp) . "
";
            $errstring .= xml_error_string(xml_get_error_code($this->xp) );
            $this->errstring = "XML parser error: " . $errstring ;
            // destroy parser
            xml_parser_free($this->xp);
            Return False;
        }   
        // Success 
        // destroy parser
        xml_parser_free($this->xp);
        Return True;
    }
    
    Function elementBegin($xp, $name, $attributes)
    {   
        //file_log( "Attributes: " . $attributes . "rn" );
        // opening tag handler
        $this->g_amc++;
        $amc = $this->g_amc;
        $level = $this->g_level ++;
        //file_log( "Level: " . $level . "rn" );
        $this->g_elements[ $level -1 ] = $name;
        // export the name of the current tag to the global scope
        $this->currentTag = $name;
        $this->currentData = "";

        // Add to MV Item
        $s_level = $level;
        settype( $s_level, "string");
        $this->MVItem->replace( $s_level, $amc, 1 );
        $this->MVItem->replace( $name, $amc, 2 );
        $ename = $this->MVItem->extract( $amc , 2 );
        // Handle attributes
        $attrib = "";
        $index = 0;
        foreach ($attributes as $key => $value) {
            $index ++;
            $attrib =  trim( $key . "=" . $value );         
//          echo $attrib . " - index=$index
";
            $this->MVItem->replace( $attrib, $amc, 3, $index );
//          echo $this->MVItem->extract(  $amc, 3, $index ) . "=attrib$index
";
        }
    
    }

    Function elementEnd($xp, $name)
    {
        // closing tag handler      
//      echo $this->currentData;
        $this->MVItem->replace( trim($this->currentData), $this->g_amc, 4 );        
         
        $this->g_level --;
        $this->currentTag = $this->g_elements[ $this->g_level -1] ;
    }

    Function characterData($xp, $data)
    {
        // character data handler
        $data = Trim( $data );
        If($data != '') {
//          echo $data . "
";
            $this->currentData .= " ". $data;
//          $this->MVItem->replace( $data, $this->g_amc, 4 );       
        }
    }   

    Function GetMVItem()
    {
        Return $this->MVItem;
    }   
}
?>

MVItem

mvKey = $key;
        $this->mvObj = $item;
    }
    
    function getFormattedItem(){
        $this->mvKey = _MV_WRITE_._MV_SEP_._MV_SEP_.$this->mvKey._MV_SEP_.$this->mvObj->toString()._MV_SEP_;
        return $this->mvKey;
    }
    
 } // MVFile

class MVItem {
    var $Record;
    var $origrec;
    
    function __construct($rec = ""){
        if(empty($rec)){
            $this->Record = Array();
            $this->origrec = $this->Record;
            return;
        }
        $this->setRecord($rec);
    }

    function setRecord($newval){
        $rec = explode(_MV_AM_,$newval);
        $nbam = count($rec);
        $this->Record = Array();
        $this->origrec = $newval;
        for($am = 0;$am < $nbam;$am++) {
            $vam = explode(_MV_VM_,$rec[$am]);
            $nbvm = count($vam);
            $lvm = Array();
            for($vm = 0;$vm < $nbvm;$vm++){
                $vvm = explode(_MV_SVM_,$vam[$vm]);
                $lvm[$vm] = $vvm;
            }
            $this->Record[$am] = $lvm;
        }
        return true;
    }
    
    function toString(){
       return $this->extract();    
    }
    
    function extract($am = 0,$vm = 0,$svm = 0) {
        $am --;
        $vm --;
        $svm --;
        //file_log( "SVM: " . $svm . "rn" );
        if($vm == -1) $svm = -1;
        
        if($am == -1) {
            $nbam = count($this->Record);
            $res = "";
            for($am = 0;$am<$nbam;$am++) {
                $nbvm = count($this->Record[$am]);
                $lvm = Array();
                for($vm= 0;$vm<$nbvm;$vm++){
                    if(is_array($this->Record[$am][$vm])){
                       $lvm[$vm] = implode(_MV_SVM_,$this->Record[$am][$vm]);
                    }else{
                       $lvm[$vm] = $this->Record[$am][$vm];
                    }
                }
                if(is_array($lvm) ){
                   $res[$am] = implode(_MV_VM_,$lvm);
                } else {
                   $res[$am] = $lvm;
                }
            }
            if(is_array($res)) {
               return implode(_MV_AM_,$res);
            } else {
               return $res;
            }
        }
        
        if($vm == -1) {
            $nbvm = count($this->Record[$am]);
            $lvm = Array();
            for($vm= 0;$vm<$nbvm;$vm++){
                $lvm[$vm] = implode(_MV_SVM_,$this->Record[$am][$vm]);
            }
            return implode(_MV_VM_,$lvm);
        }

        if($svm == -1 ){
//          MM fix undefined offset         
            if(count($this->Record) < ( $am + 1 ) ) {
                //file_log("SVM = -1 rn");
                return "";
            }
            if(count($this->Record[$am]) < ( $vm + 1 ) ) {
                //file_log("SVM = -1 rn");
                return "";
            }
//          End Of fix  

           return implode(_MV_SVM_,$this->Record[$am][$vm]);
        } else {

            return $this->Record[$am][$vm][$svm];
        }
    }
    
    function replace($newval,$am = 0, $vm = 0 , $svm = 0){
        if($am == 0) return;
        if($vm == 0) $svm = 0;
        
        for($i=count($this->Record);$i < $am;$i++){
            $this->Record[$i]= Array(""); 
        }       
        
        if($vm == 0) {
            $this->Record[$am-1] = array($newval);    
        }else{
        
           for($i = count($this->Record[$am-1]);$i < $vm ; $i++){
                $this->Record[$am-1][$i] = Array(""); 
           }
           
           if($svm == 0) {
              $this->Record[$am-1][$vm-1] = Array($newval);
           }else{
               for($i = count($this->Record[$am-1][$vm-1]);$i < $svm ; $i++){
                    $this->Record[$am-1][$vm-1][$i] = Array(""); 
               }
//               $this->Record[$am-1][$vm-1][$svm-1] = Array($newval);
               $this->Record[$am-1][$vm-1][$svm-1] = $newval;
           }
        }
    }

    function ins(&$tab,$pos,$newval){
        $fin = $tab;
        $nb = count($tab);
        array_splice($tab,-($nb-$pos),($nb-$pos));
        array_splice($tab,-1,1,array($newval,""));
        array_splice($fin,0,($pos-1));
        array_splice($tab,-1,1,$fin);
    }
        
    function insert($newval, $am = 0,$vm = 0,$svm = 0){
        if($am == 0) return;
        if($vm == 0) $svm = 0;
        
        if ($am > count($this->Record) ) {
            $this->replace($newval,$am);
            return;
        }
        
        if($vm == 0) {
            $this->ins($this->Record,$am,array($newval));
        }else{
            if($vm > count($this->Record[$am-1])) {
                $this->replace($newval,$am,$vm);
                return;
            }
           
            if($svm == 0) {
               $this->ins($this->Record[$am-1],$vm,$newval);
            }else{
               for($i = count($this->Record[$am-1][$vm-1]);$i < $svm -1 ; $i++){
                   $this->Record[$am-1][$vm-1][$i] = Array(""); 
               }

               $this->ins($this->Record[$am-1][$vm-1],$svm,$newval);
            }
        }
    }
    
    function delete($am = 0 ,$vm = 0,$svm = 0) {
        if($am == 0) return;
        if($vm == 0) $svm =0;
        
        if($vm == 0){
           array_splice($this->Record,$am - 1,1);
        }else{
           if($svm == 0) {
                array_splice($this->Record[$am-1],$vm - 1,1);
           }else{
                array_splice($this->Record[$am-1][$vm-1],$svm - 1,1);
           }
        }
           
    }
    
    function AMCount(){
//MM
//echo '<' . count( $this->Record ) . '>';
        return count($this->Record);
    }
    
    function VMCount($am){
        if ($am > count($this->Record) || $am == 0) return 0;
        $tmp = $this->Record[$am-1];
        
        return count($tmp);
    }
    
    
    function SVMCount($am,$vm){
        if ($am > count($this->Record) || $am == 0) return 0;
        
        $tmp = $this->Record[$am-1];

        if ($vm > count($tmp) || $vm == 0 ) return 0;
        
        $tmp = $tmp[$vm-1];
        
        return count($tmp);
    }
    
    
  } // MVItem
 
}
?>

以下是在PHP 5.4中的正确返回值

Creating XML Parser.
Parsing XML to MV item.
Getting formatted output.
MVItem Object ( [Record] => Array ( [0] => Array ( [0] => Array ( [0] => 0 ) [1] => Array ( [0] => Test ) [2] => Array ( [0] => ) [3] => Array ( [0] => ) ) ) [origrec] => Array ( ) ) 1
Formatted output: 101234567890�Test��

以下是我在PHP 7.4中得到的结果：

Creating XML Parser.
Parsing XML to MV item.
Getting formatted output.
MVItem Object ( [Record] => Array ( [0] => Array ( [0] => Array ( [0] => 0 ) [1] => Array ( [0] => Test ) [2] => Array ( [0] => ) [3] => Array ( [0] => ) ) ) [origrec] => Array ( ) ) 1
Formatted output: 101234567890

XML解析器应该是没问题的，因为返回的数组是相同的。真正的问题在于getFormattedItem()方法，它实际上只是涉及到extract()方法。已经尝试在各个位置添加打印语句，但似乎无法确定哪个语句导致了问题。