if statements test a control statement to see whether it is
true or false.
else and elsif clauses can also be tagged on the back.
#your basic if
if($value==1){
print "value is equal to 1\n";
}
#your basic if/else
if($value==1){
print "value is equal to 1\n";
} else{
print "value is not equal to 1\n";
}
#your basic if/elsif/else
if($value==1){
print "value is equal to 1\n";
} elsif($value==2){
print "value is equal to 2\n";
} elsif($value==3){
print "value is equal to 3\n";
} else{
print "value is not equal to 1,2, or 3\n";
}
Unless statements offer you the opposite functionality. If the control statement evaluates
to false then the statements inside the block are executed.