How to avoid common Perl errors
This article mainly introduces how to avoid common Perl errors, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.
Five common Perl errors
I've been making things with Perl+mdbm+spread recently.
Php has been used for a long time, python and ruby have been used, but Perl has never touched the classic scripting language, and now it is holding a textbook like a primary school student. I found that Perl is really much more difficult. Other things don't make me make mistakes so often.
1. Output * A common Perl error is to output content to a file. The standard syntax is:
PrintSTDERR "thisisanapple."
It's usually written as
PrintSTDERR, "thisisanapple."
Always put an extra comma. To be honest, I seldom make mistakes repeatedly, but I just can't remember this place.
two。 The second common Perl error is that arrows referenced by Hash are often omitted.
It should have been written
Print$hash- > {$key}
Is often written as
Print$hash {$key}
3. The third common Perl error is string comparison:
Php has been used for a long time, always using two equal signs to compare strings. This is wrong. The correct way to write is
If ($vareq "hello") {
Print "world"
}
It is often written as:
If ($var== "hello") {
Print "world"
}
This can lead to logical errors that are difficult to detect.
4. The fourth common Perl error: if statements without parentheses (all bad by php)
The correct way to write it is:
If ($var)
{
Print "yes"
}
Is often written as
If ($var)
Print "yes"
5. There is another Perl error: if it is not brought from php, most people will not make it: omitting semicolons.
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