Perl For Loop

The Perl for loop is used to loop through a block of code until a specified condition is met. The for loop statement contains three sections followed by a block of code. Below is an example.

A Simple For Loop Example

for (my $number = 1; $number <= 10; $number++) {
  print "$number ";
}

The first section initializes a variable

my $number = 1;

Then, the loop condition is provided. The loop will run as long as this is true.

$number <= 10;

Finally, the last section is executed at the end of each loop iteration. In our example's case, $number increments by one.

$number++

Executing this loop results in:

1 2 3 4 5 6 7 8 9 10

For Loop and Arrays

Here is an example of how the for statement can be used to loop through an array.

my @languages = ("Perl", "Python", "C", "Fortran");
my $size = @languages;
for (my $i = 0; $i <= $size; $i++) {
  print "$languages[$i]\n";
}


Comments

There is very, *very* rarely

There is very, *very* rarely any reason to use a C-style for loop in Perl. Your examples would be done much more easily (and with much less chance of bounds-checking errors) with:
for my $number (1..10) {
print "$number ";
}

and
my @languages = ("Perl", "Python", "C", "Fortran");
for my $language (@languages) {
print "$language\n";
}

Or, if you need the index of the language for some other purpose,
my @languages = ("Perl", "Python", "C", "Fortran");
for my $i (0..$#languages) {
print "$languages[$i]\n";
}

+1 ;)

+1 ;)