警告：PHP 8.0 中未定义的数组键答案

【问题标题】：Warning: Undefined array key in PHP 8.0警告：PHP 8.0 中未定义的数组键
【发布时间】：2021-11-09 22:43:31
【问题描述】：

我的 webhotel 已升级到 PHP 8.0 版代码正在运行，但它现在在主页上显示警告消息。

我的数组有点问题。

Warning: Undefined array key "JS" in /customers/c/c/4/plf1x2.dk/httpd.www/test/svspeuro.php on line 1465 
Warning: Undefined array key "Vinst" in /customers/c/c/4/plf1x2.dk/httpd.www/test/svspeuro.php on line 1465 
Warning: Undefined array key "PWB" in /customers/c/c/4/plf1x2.dk/httpd.www/test/svspeuro.php on line 1468 Warning: 
Undefined array key "Vinst" in /customers/c/c/4/plf1x2.dk/httpd.www/test/svspeuro.php on line 1468 Warning: 
Undefined array key "oavgjord" in /customers/c/c/4/plf1x2.dk/httpd.www/test/svspeuro.php on line 1471  here

我试过了

enterif (isset($matchesLines[$Borta_Lag]['omgångar'])){
    $matchesLines[$Borta_Lag]['omgångar']+=1;
    } code here

但它不起作用，它得到一个空值。

这里是代码。我希望有人能帮助我吗？

// Sorterar ut lagnamn och resultat
$file = file($filename);
$result = array_merge($file,$resultatarray)
$matchesLines = array();


foreach($result as $line) {

  if(preg_match('/^([a-öA-Ö]+\D)-([a-öA-Ö]+\D) (\d+)-(\d+)/',  $line,  $data)){
    $Hemma_Lag = $data[1];
    $Borta_Lag = $data[2];
    $Hemma_Resultat = $data[3];
    $Borta_Resultat=$data[4];

    $matchesLines[$Hemma_Lag]['Vinst'] += 0;
    $matchesLines[$Borta_Lag]['Vinst'] += 0;
    $matchesLines[$Hemma_Lag]['oavgjord'] += 0;
    $matchesLines[$Borta_Lag]['oavgjord'] += 0;
    $matchesLines[$Hemma_Lag]['Förlust'] += 0;
    $matchesLines[$Borta_Lag]['Förlust'] += 0;

    if ($Hemma_Resultat == $Borta_Resultat){
      $matchesLines[$Hemma_Lag]['lag'] = $Hemma_Lag;
      $matchesLines[$Hemma_Lag]['poang']+=1;
      $matchesLines[$Hemma_Lag]['mål'] += $Hemma_Resultat;
      $matchesLines[$Hemma_Lag]['måli'] += $Borta_Resultat;
      $matchesLines[$Hemma_Lag]['oavgjord'] += 1;
      $matchesLines[$Borta_Lag]['lag'] = $Borta_Lag;
      $matchesLines[$Borta_Lag]['poang'] +=1;
      $matchesLines[$Borta_Lag]['mål'] += $Borta_Resultat;
      $matchesLines[$Borta_Lag]['måli'] += $Hemma_Resultat;
      $matchesLines[$Borta_Lag]['oavgjord'] += 1;
    }

    if ($Hemma_Resultat > $Borta_Resultat){
      $matchesLines[$Hemma_Lag]['lag'] = $Hemma_Lag;
      $matchesLines[$Hemma_Lag]['poang']+=3;
      $matchesLines[$Hemma_Lag]['mål'] += $Hemma_Resultat;
      $matchesLines[$Hemma_Lag]['måli'] += $Borta_Resultat;
      $matchesLines[$Hemma_Lag]['Vinst'] += 1;
      $matchesLines[$Borta_Lag]['lag'] = $Borta_Lag;
      $matchesLines[$Borta_Lag]['poang'] +=0;
      $matchesLines[$Borta_Lag]['mål'] += $Borta_Resultat;
      $matchesLines[$Borta_Lag]['måli'] += $Hemma_Resultat;
      $matchesLines[$Borta_Lag]['Förlust'] += 1;
    }

    if ($Hemma_Resultat < $Borta_Resultat) {
      $matchesLines[$Hemma_Lag]['lag'] = $Hemma_Lag;
      $matchesLines[$Hemma_Lag]['poang']+=0;
      $matchesLines[$Hemma_Lag]['Förlust'] += 1;
      $matchesLines[$Hemma_Lag]['mål'] += $Hemma_Resultat;
      $matchesLines[$Hemma_Lag]['måli'] += $Borta_Resultat;
      $matchesLines[$Borta_Lag]['lag'] = $Borta_Lag;
      $matchesLines[$Borta_Lag]['poang'] +=3;
      $matchesLines[$Borta_Lag]['Vinst'] += 1;
      $matchesLines[$Borta_Lag]['mål'] += $Borta_Resultat;
      $matchesLines[$Borta_Lag]['måli'] += $Hemma_Resultat;
    }
    
    if (isset($matchesLines[$Borta_Lag])){
    $matchesLines[$Borta_Lag]['omgångar']+=1;
    $matchesLines[$Hemma_Lag]['omgångar']+=1;
    }

  }

}

【问题讨论】：

我不认为这是 PHP 8 特有的东西。我认为这可能只是您更新的 PHP 版本中 php.ini 中 display_errors 设置的不同。由于未初始化的变量，我认为您之前已经收到了这些警告，但它们只是没有显示出来。
感谢您的回复。我想你是对的。但问题仍然存在。如何摆脱按摩？我不明白如何声明变量。
@Don'tPanic 不，这是 PHP 8.0 的提升
@Martin 哦，是的，你是对的。
@Don'tPanic 我刚刚发现了它，这让我有些难过......我的错误日志不再为空:-(

标签： php arrays key undefined

【解决方案1】：

是的，PHP 8.0 has elevated 这条通知和一堆其他通知现在是警告：

一些通知已转换为警告：

Attempting to read an undefined variable.
Attempting to read an undefined property.
Attempting to read an undefined array key.
...

【讨论】：