what is the difference between the \L and the lc function in Perl?

Question

What is the difference between \\L and lc in Perl?

Where are these two applicable?

Answer 1

"foo\Lbar\Ebaz"

is just another way of writing

"foo".lc("bar")."baz"

It happens after interpolation, so

"foo\L$bar\Ebaz"

is just another way of writing

"foo".lc($bar)."baz"

\\L..\\E is useful in the substitution operator's replacement expression which is a string literal.

s/(...)(...)(...)/\L$1\E!$2!\L$3\E/

To use lc , you'd have to use /e

s/(...)(...)(...)/ lc($1)."!$2!".lc($3) /e

Answer 2

lc is a function that takes an expression and returns the lowercase version of that expression. \\L is used as a way to make letters in a substring lower case (is terminated by \\E )

For example:

print lc("STeve");
#prints steve  

print "DOW\LNLO\EAD\n";
#prints DOWnloAD