Hello

Here is something I stumbled across: 

print "hello" if 1;
# prints hello
print "hello" if 0;
# doesn't print anything
print "hello" if "1";
# prints hello again
print "hello" if "0";
# Useless use of a constant in void context at ./test.pl line 3.

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This error occurs only if the program is in a file (ie perl -e 'print "hello" if "0"' works as advertized). Could anybody enlighten me for the reason for this seemingly strange behavior?

PS: ("0" and print "hello") fails for the exact reason since perl translates (print "hello" if "0") to ("0" and print "hello") at compile time if I remember the perl parser correctly.

In reply to if "0" by abstracts

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