PHP 错误：未定义的偏移量：1
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PHP Error: Undefined offset: 1
提问by eightonrose
It seems like this might be an error dealing with arrays, but I can't figure it out. I'm really just starting with PHP and this is getting to be a little intimidating. Any help would be greatly appreciated! here is my code:
看起来这可能是处理数组的错误，但我无法弄清楚。我真的只是从 PHP 开始，这有点令人生畏。任何帮助将不胜感激！这是我的代码：
<?php echo "<h1>Choose a Poll!</h1>";
$read = file('poll_topics.txt');
$data = array( );
foreach($read as $lines){
list($key,$v) = explode("|","$lines");
$data[$key] = $v;
}
foreach ($data as $k=>$desc){
echo "<ul><li><a href='take_a_poll.php?poll=$k'>$k</a> - $desc </li></ul>";
}
?>
Here is what is in the text file:
这是文本文件中的内容：
Instruments|What kind of instruments do you like?
Music|What type of music do you like best?
I should clarify:
The error is line 20, or where it says list($key,$v) = explode...
我应该澄清：错误是第 20 行，或者它说的地方 list($key,$v) = explode...
回答by mario
You have an empty line somewhere. That's why explode()will return only an empty $key, but have nothing to assign to the $v. And that's when it prints that notice.
你在某处有一个空行。这就是为什么explode()只会返回一个空的 $key，而没有任何东西可以分配给 $v。这就是它打印该通知的时候。
You can rewrite it a bit to ignore such cases:
您可以稍微重写一下以忽略此类情况：
foreach ($read as $lines) {
$key = strtok($lines, "|");
$v = strtok("|");
if ($v) {
$data[$key] = $v;
}
}
This will also avoid an empty entry in your final $data array.
这也将避免在最终的 $data 数组中出现空条目。
回答by lucifurious
Try this:
尝试这个：
<?php
echo "<h1>Choose a Poll!</h1>";
$_fileData = file_get_contents('poll_topics.txt');
$_results = array();
if ( ! empty( $_fileData ) )
{
foreach ( $_fileData as $_line )
{
$_split = explode( '|', $_line );
// Many ways to do this:
// if ( !empty( $_split ) && 2 == count( $_split ) ) then no error else error
// or...
if ( isset( $_split[0], $_split[1] ) )
{
$_key = $_split[0];
$_value = $_split[1];
if ( null !== $_key && null !== $_value )
{
$_results[ $_key ] = $_value;
// or $_results[] = array( $_key => $_value ); if key can be duplicated
}
}
}
}
回答by Keziah Kitone
You could try to use the array_pad()function.
Use it where you wrote the explode function.
您可以尝试使用该array_pad()功能。在您编写爆炸函数的地方使用它。
$_split = array_pad(explode( '|', $_line ), numberOfElementsInArray, null);
