注意：未定义的偏移量 php

Question

我有这个 php 代码会引发警报 notice: undefined offset

$thisMonth=$_POST['month']; //the value is today's date's month
$thisYear=$_POST['year']; //the value is today's date's year
$thisDay=$_POST['day']; //the value is today's date's day

$table=mysql_query("SELECT * FROM `kids` WHERE `debt`!='0'") or die(mysql_error());
$debt=0;

while($row=mysql_fetch_assoc($table)){
    $explodedDate=explode('/',$row['enrollmentdate']);
    $theYear=$explodedDate[0];
    $theMonth=$explodedDate[1]; //this line throws the error
    $theDay=$explodedDate[2]; //and also this line
    if((int)$theYear==(int)$thisYear && (int)$theMonth==(int)$thisMonth){
        if((int)$theDay==(int)$thisDay || (int)$thisDay==0){
            $debt+=$row['debt'];
            }
        }
    }

我一直在互联网上阅读解决方案，但似乎此错误取决于代码，不幸的是我似乎无法弄清楚如何修复它。

任何想法如何解决错误或导致错误的原因？

这是完整的错误：

注意：未定义的偏移量：C:\wamp\www\kids_house\php\functions.php 第 600 行中的 1 注意：未定义的偏移量：C:\wamp\www\kids_house\php\functions.php 第 601 行中的 2

Answer 1

这两行抛出错误的原因是因为这里的值不是你期望的yyyy/mm/dd：

$explodedDate=explode('/',$row['enrollmentdate']);

如果你用这样的方式查看引发错误的值，你应该会看到问题：

$thisMonth=$_POST['month']; //the value is today's date's month
$thisYear=$_POST['year']; //the value is today's date's year
$thisDay=$_POST['day']; //the value is today's date's day

$table=mysql_query("SELECT * FROM `kids` WHERE `debt`!='0'") or die(mysql_error());
$debt=0;

while($row=mysql_fetch_assoc($table)){
    $explodedDate=explode('/',$row['enrollmentdate']);

    if ( count( $explodedDate ) <= 1 ) {
        var_dump( $row );   //this will show you the row that is causing the notice
        var_dump( $explodedDate );   //this will show you the date
        die();
    }

    $theYear=$explodedDate[0];
    $theMonth=$explodedDate[1]; //this line throws the error
    $theDay=$explodedDate[2]; //and also this line
    if((int)$theYear==(int)$thisYear && (int)$theMonth==(int)$thisMonth){
        if((int)$theDay==(int)$thisDay || (int)$thisDay==0){
            $debt+=$row['debt'];
            }
        }
    }

如果您想用逗号重试注册日期格式为 yyyy,mm,dd 的行，您可以这样做。这不是最优雅的解决方案，但听起来你有脏数据，所以可能不得不这样做。

$thisMonth=$_POST['month']; //the value is today's date's month
$thisYear=$_POST['year']; //the value is today's date's year
$thisDay=$_POST['day']; //the value is today's date's day

$table=mysql_query("SELECT * FROM `kids` WHERE `debt`!='0'") or die(mysql_error());
$debt=0;

while($row=mysql_fetch_assoc($table)){
    $explodedDate=explode('/',$row['enrollmentdate']);

    //try again with commas
    if ( count( $explodedDate ) == 0 ) {
        $explodedDate=explode(',',$row['enrollmentdate']);         
    }

    //skip the record if still no enrollment date
    if ( count( $explodedDate ) == 3 ) {

        $theYear=$explodedDate[0];
        $theMonth=$explodedDate[1]; //this line throws the error
        $theDay=$explodedDate[2]; //and also this line
        if((int)$theYear==(int)$thisYear && (int)$theMonth==(int)$thisMonth){
            if((int)$theDay==(int)$thisDay || (int)$thisDay==0){
                $debt+=$row['debt'];
                }
            }
        }
    }