Hi All,
I am wondering why $test1 the code below stays 0. 
sub test{
  my $i = shift;
  my $params = shift;
  my $test1 = $params->{test} if exists $params->{test};
  print "test1 after hash assignment:\t\t$test1\n";
  $test1 = $i if ! defined $test1;
  print "i = $i\ttest1 after defaulting to i:\t$test1\n";
}

for my $i(0..3){
  &test($i,{});
}

[download]

Output: 
Use of uninitialized value $test1 in concatenation (.) or string at te
+st.pl line 19.
test1 after hash assignment:        
i = 0    test1 after defaulting to i:    0
test1 after hash assignment:        0
i = 1    test1 after defaulting to i:    0
test1 after hash assignment:        0
i = 2    test1 after defaulting to i:    0
test1 after hash assignment:        0
i = 3    test1 after defaulting to i:    0
<br>

[download]

I figured out that the line my $test1 = $params->{test} if exists $params->{test}; causes the trouble, but I am wondering why.
Thanks!

In reply to postfix syntax enlightenment by RobertCraven

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