Should Local Variable Initialisation Be Mandatory?

Question

The maintenance problems that uninitialised locals cause (particularly pointers) will be obvious to anyone who has done a bit of c/c++ maintenance or enhancement, but I still se

Answer 1

In C/C++ I totally agree with you.

In Perl when I create a variable it is automatically put to a default value.

my ($val1, $val2, $val3, $val4);
print $val1, "\n";
print $val1 + 1, "\n";
print $val2 + 2, "\n";
print $val3 = $val3 . 'Hello, SO!', "\n";
print ++$val4 +4, "\n";

They are all set to undef initially. Undef is a false value, and a place holder. Due to the dynamic typing if I add a number to it, it assumes that my variable is a number and replaces undef with the eqivilent false value 0. If i do string operations a false version of a string is an empty string, and that gets automatically substituted.

[jeremy@localhost Code]$ ./undef.pl

1
2
Hello, SO!
5

So for Perl at least declare early and don't worry. Especially as most programs have many variables. You use less lines and it looks cleaner without explicit initializing.

 my($x, $y, $z);

:-)

 my $x = 0;
 my $y = 0;
 my $z = 0;