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Perl provides a shortcut for writing "$myvar = $myvar + $value", or "$myvar = $myvar / $value" and similar operations. Here's an example:
$x = 1; $y = 0; print "2^", $y, "=", $x, "\n"; $x *= 2; $y += 1; print "2^", $y, "=", $x, "\n"; $x *= 2; $y += 1; print "2^", $y, "=", $x, "\n"; $x *= 2; $y += 1; print "2^", $y, "=", $x, "\n"; $x *= 2; $y += 1; print "2^", $y, "=", $x, "\n"; $x *= 2; $y += 1; print "2^", $y, "=", $x, "\n";
Since the operations $x += 1 and $x -= 1 are so commonly used, they were also assigned a separate operator. One can use $x++ and $x-- to perform them. For example, the above program could have been written as:
$x = 1; $y = 0; print "2^", $y, "=", $x, "\n"; $x *= 2; $y++; print "2^", $y, "=", $x, "\n"; $x *= 2; $y++; print "2^", $y, "=", $x, "\n"; $x *= 2; $y++; print "2^", $y, "=", $x, "\n"; $x *= 2; $y++; print "2^", $y, "=", $x, "\n"; $x *= 2; $y++; print "2^", $y, "=", $x, "\n";
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Written by Shlomi Fish