in reply to Re: /e in regexes
in thread /e in regexes

Thanks. But why a single /e is enough in the first case then?

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Re^3: /e in regexes
by moritz (Cardinal) on Jun 22, 2008 at 16:48 UTC
    Because in this cases the evaluated string is "10" + 1, which forces perl to treat "10" as a number. If your evaluated string is "10+1", The whole thing is taken as a string literal.
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Re^3: /e in regexes
by ikegami (Patriarch) on Jun 22, 2008 at 16:59 UTC

    In one case, you want the replacement expression to be a Perl expression,
    In the other, you want the value of $1 to be evaluated. 

    # s/(10)/$1+1/e
$dollar1 = "10";
$replace = $dollar1 + 1;   # One 'e', so Perl expression.
print $replace;            # 11

# s/(10\+4)/$1/e
$dollar1 = "10+4";
$replace = $dollar1;       # One 'e', so Perl expression.
print $replace;            # 10+4

# s/(10\+4)/$1/ee
$dollar1 = "10+4";
$replace = eval $dollar1;  # Two 'e', so Perl expression + eval.
print $replace;            # 14

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    Update: Oops, this was supposed to be a reply to Re^2: /e in regexes.

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      Thanks everybody. Thanks to this last example it's clear now (I hope).
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