我如何执行字符串上的 Perl 替换，同时保留原来的？

Question

In Perl, what is a good way to perform a replacement on a string using a regular expression and store the value in a different variable, without changing the original?

I usually just copy the string to a new variable then bind it to the s/// regex that does the replacement on the new string, but I was wondering if there is a better way to do this?

$newstring = $oldstring;
$newstring =~ s/foo/bar/g;

转载于:https://stackoverflow.com/questions/22836/how-do-i-perform-a-perl-substitution-on-a-string-while-keeping-the-original

Answer 1

This is the idiom I've always used to get a modified copy of a string without changing the original:

(my $newstring = $oldstring) =~ s/foo/bar/g;

In perl 5.14.0 or later, you can use the new /r non-destructive substitution modifier:

my $newstring = $oldstring =~ s/foo/bar/gr; 

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Note: The above solutions work without g too. They also work with any other modifiers.