Increment operator

Increment operator "++"

Using the increment operator , assigned to variable You can add 1 to the number. The increment operator can be added before or after the variable.

# Increment (postfix)
$num ++;

# Increment (prefix)
++ $num;

The increment operator has the same meaning as the following description using addition operator.

$num = $num + 1;

The increment operator is often used in for statement.

for (my $i = 0; $i < 10; $i++) {
  print "$i\n";
}

This example program outputs 0 to 10.

Difference between prefix increment and suffix increment

Prefix increments and postfix increments have the same meaning when used alone, but have different meanings when a return value is used, such as being assigned.

Prefix increment

For prefix increments, the incremented value is returned.

my $num1 = 0;
my $num2 = ++ $num;

"$Num1" is incremented to 1. This value of 1 is returned and assigned to "$num2".

I explained in the case of assignment, but I will also give an example of passing a value to subroutine. The fun is passed a incremented value .

func (++ $i);

Postfix increment

For prefix increments, the value before the increment is returned.

my $num1 = 0;
my $num2 = $i++;

"$Num1" is incremented to 1, but the value before the increment, 0, is assigned to $num2.

The above two have different values in $k. In the first case, $k contains 1. In the second case, $k will be 0.

I explained in the case of assignment, but I will also give an example of passing a value to a subroutine. The fun is passed the value before it was incremented .

func ($i++);

Decrement operator

The decrement operator is the opposite of the increment operator, which allows you to subtract 1. The decrement operator is explained in detail below.

Decrement operator

Perl ABC