为什么这个 for 循环会在 while 条件之前退出？

发布于 2024-10-25 22:59:48 字数 685 浏览 3 评论 0原文

我正在读取一个文件并执行一个 while 循环来迭代运行文件中的每一行。在 while 循环内，我有一个 if 条件，其中有一个嵌套的 for 循环，该循环执行一些过程。发生的情况是，尽管保持 while 循环运行的条件仍然有效，但 for 循环完成后代码就会退出。

my $datafile = "data.txt";
open my $fh, "<", $datafile or die "Failed to open $datafile ($!)";

my $csv = Text::CSV->new() or die "Failed to create Text::CSV object";
my $line = <$fh>;

while ($line = <$fh>)
{ 
    blah blah
    blah blah

    if ($foo > $cow) {
        blah
    } elsif ($foo == $cow) { 
        blah
    } else {
        for ($i =1; $i <= $something; $i++) {
            blah blah
        }
    }
}

问题是代码没有完成遍历 data.txt 文件的每一行。 for 循环完成后，代码就会退出。

任何见解将不胜感激。谢谢。

原文

I am reading a file and executing a while loop to iteratively run through each line in the file. Inside the while loop I have a if condition which has a nested for loop which does some processes. What happens is that the code exits once the for loop finishes despite the fact that the condition to keep the while loop running is still valid.

my $datafile = "data.txt";
open my $fh, "<", $datafile or die "Failed to open $datafile ($!)";

my $csv = Text::CSV->new() or die "Failed to create Text::CSV object";
my $line = <$fh>;

while ($line = <$fh>)
{ 
    blah blah
    blah blah

    if ($foo > $cow) {
        blah
    } elsif ($foo == $cow) { 
        blah
    } else {
        for ($i =1; $i <= $something; $i++) {
            blah blah
        }
    }
}

The problem is the code is not finished going through every line of the data.txt file. The code exits once it finishes with the for loop.

Any insight would be greatly appreciated. Thank you.

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