Programming

Here you can see multiple ways of implementing array iterator.

Example1:

This example reads each element of the array to a variable “$item” in a loop.

@myarray = ('One', 'Two', 'Three');
foreach $item (@myarray) {
  print $item;
}

Example2:

This example avoids intermediate variable “$item” shown in the above script. However if you have nested loops, this method is not suitable. Each element is available in a special variable “$_” inside the loop.

@myarray = ('One', 'Two', 'Three');
foreach (@myarray) {
  print $_;
}

Example3:

This example is similar to “for” loop style of a C programmer .

@myarray = ('One', 'Two', 'Three');
for($i=0; $i <= $#myarray; More >

The following perl script reads one line at a time from the standard input which can be from normal console or a redirected file using pipes.

[nick@techpulp ~]# cat readline.pl
#!/usr/bin/perl

$line = 0;
while (<>) {
  $line++;
  print "Line $line: " . $_;
}
[nick@techpulp ~]# chmod +x readline.pl
[nick@techpulp ~]#

In the above script, The “<>” reads a line from standard input file of the script and “$_” contains the last read data.

For input, let us consider following file (input.txt) which contains four lines.

[nick@techpulp ~]# cat input.txt
first line
second line
third line
fourth line
[nick@techpulp ~]#

Now let More >