Control Structures

Control structures are features of programming languages that influence the code flow. Two common examples are loops and conditions. This task here is to demonstrate control structures supported by different programming languages.

Perl

if-then-else

Interpreter: Perl 5.8.8

#!/usr/bin/perl -w

use strict;

my $condition1 = 0;
my $condition2 = 1;

if ( $condition1 ) {
 # Do something
}

if ( $condition1 ) {
 # Do something
} elsif ( $condition2 ) {
 # Do somethine else
}

if ( $condition1 ) {
 # Do something
} else {
 # Do something else
}

if ( $condition1 ) {
 # Do something
} elsif ( $condition2 ) {
 # Do something else
} else {
 # Do that other thing
}

unless

Interpreter: Perl 5.8.8

#!/usr/bin/perl -w

use strict;

my $condition1 = 0;

unless ( $condition1 ) {
  # Do something
}

unless ( $condition1 ) {
  # Do something
} else {
  # Do something else
}

while

Interpreter: Perl 5.8.8

#!/usr/bin/perl -w

use strict;

my $condition1 = 0;

while ( $condition1 ) {
 # Do something.
 # Remember to change the value of condition1 at some point.
}

do-while

Interpreter: Perl 5.8.8

#!/usr/bin/perl -w

use strict;

my $condition1 = 0;

do {
 # Do something.
 # Remember to change the value of condition1 at some point.
} while ( $condition1 );

until

Interpreter: Perl 5.8.8

#!/usr/bin/perl -w

use strict;

my $condition1 = 1;

until ( $condition1 ) {
 # Do something.
 # Remember to change the value of condition1 at some point.
}

do-until

Interpreter: Perl 5.8.8

#!/usr/bin/perl -w

use strict;

my $condition1 = 1;

do {
 # Do something.
 # Remember to change the value of condition1 at some point.
} until ( $condition1 );

for

Interpreter: Perl 5.8.8

#!/usr/bin/perl -w

use strict;

my $limit = 5;

for ( my $iterator = 0; $iterator < $limit; $iterator++ ) {
  # Do something
}

foreach

Interpreter: Perl 5.8.8

#!/usr/bin/perl -w

use strict;

my @array = ( 'Value1', 'Value2', 'Value3' );

foreach (@array) {
  my $arrayitem = $_;
  # Do something
}