Two methods of generating excel table with PHP

$html = data ;

1. ordinary excel surface , Cannot set style , Fast

        $filename = ' Table name '.date('YmdHis');
        $header = array('a','b','c','d');// Header
        $index = array('key1','key2','key3','key4');// key

        header("Content-type:application/vnd.ms-excel");
        header("Content-Disposition:filename=".$filename.".xls");// Different from the second method

      $teble_header = implode("\t",$header);
      $strexport = $teble_header."\r";
        foreach ($html as $row){
            foreach($index as $val){
                $strexport.=$row[$val]."\t";
            }

            $strexport.="\r";
        }
        $strexport=iconv('UTF-8',"GB2312//IGNORE",$strexport);// Different from the second method
        exit($strexport);// Different from the second method

2. In tabular form

    header("Content-type:application/vnd.ms-excel");

    header("Content-Disposition:attachement;filename=avvaa".date("Ymd").".xls");// Different from the first method

   

        $html = '';
        $html .= "<table><tr>";
        // Export header （ That is, the fields in the table ）
        $html .= "<th>1</th><th>2</th><th>3</th><th>4</th><th>5</th><th>6</th>";
        $html .= "</tr>";

        for($i=0;$i<4;$i++){
            $html .= "<tr><td>a</td><td>b</td><td>c</td><td>d</td><td>e</td><td>f</td></tr>";
        }
        $html.= "</table>";
        $html = mb_convert_encoding($html,"gb2312","utf-8");;// Different from the first method
        echo $html;;// Different from the first method

summary ： There is a difference between the header and the following output , The first form cannot be generated excle surface