Operations and Assignment

Once we have declared variables, we can now perform comutations using them. To do this we need to look at a few operators. Perl uses all the usual C arithmetic operators:

$a = 1 + 2; # Add 1 and 2 and store in $a

$a = 3 - 4; # Subtract 4 from 3 and store in $a

$a = 5 * 6; # Multiply 5 and 6

$a = 7 / 8; # Divide 7 by 8 to give 0.875

$a = 9 ** 10; # Nine to the power of 10

$a = 5 % 2; # Remainder of 5 divided by 2

++$a; # Increment $a and then return it

$a++; # Return $a and then increment it

--$a; # Decrement $a and then return it

$a--; # Return $a and then decrement it

and for strings Perl has the following among others:

$a = $b . $c; # Concatenate $b and $c

$a = $b x $c; # $b repeated $c times

To assign values Perl includes

$a = $b; # Assign $b to $a

$a += $b; # Add $b to $a

$a -= $b; # Subtract $b from $a

$a .= $b; # Append $b onto $a

Note that when Perl assigns a value with $a = $b it makes a copy of $b and then assigns that to $a. Therefore the next time you change $b it will not alter $a.

You can find many more perl opperators on the perlop manual page. Type man perlop at the prompt.