The 0xNNNN notation is a source-code feature. It is parsed at compile-time. So this works:

my $n = 0xDEADBEEF;
print "$n\n";

# Output:
# 3735928559

[download]

And this works but you shouldn't use it:

# This works but is NOT recommended, and can be unsafe.
my $n = eval "0xDEADBEEF";
print "$\n";

# Output:
# 3735928559

[download]

That second example works because even though we've created a string of characters, "0xDEADBEEF", the eval statement evaluates that string as source code, so it gets parsed and compiled when the statement is executed at runtime.

This doesn't work:

my $n = "0xDEADBEEF";
print "$n\n";

# Output:
# 0xDEADBEEF

[download]

It didn't work because the string was taken as plain old characters. Since you want to take a string of characters and interpret them as a hex digits you should use the hex function:

This is the version you should use:

my $string = "DEADBEEF";
my $n = hex($string);
print "$n\n";

# Output:
# 3735928559

[download]

Dave

In reply to Re: hex numbers by davido
in thread hex numbers by LloydRice

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