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Operators at
a Glance
Operators make up the foundation of a perl script's comparison,
logic, and arithmetic processing. I would say that 9 out of
10 scripts have operators in them. If you have taken any math
class or any other kind of programming language then you will
most likely be familiar with the many types of operators.
Below, I will explain their functions in dealing with perl
scripts.
Arithmetic Operators
Arithmetic Operators generally perform mathematical
calculations on numbers. The key word here is numbers.
Do not mistakenly use these types of operators when trying
to combine strings...there are special operators for this
purpose. The following table outlines the different arithmetic
operators used widely in perl scripts:
| + |
Addition
of two or more numbers |
| - |
Subtraction,
Negative Numbers, Unary Negation |
| * |
Multiplication
of two or more numbers |
| / |
Division
of two or more numbers |
| ** |
Exponential |
| % |
Modulus |
There would obviously be many uses for these types of operators
in today's world, ranging from accounting packages to a simple
web site counter... below is some sample code to get your
feet wet:
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#
This calculation will find total web page visits for
1
# year assuming we know each months' visits
$january=345;
$february=256;
$march=444;
$april=541;
$may=678;
$june=350;
$july=411;
$august=398;
$september=500;
$october=758;
$november=648;
$december=1555;
# To be safe...it would be wise to place the following
# statement all on 1 line in your code...
$total_visits=$january+$february+$march+$april+$may+$june+$july+
$august+$september+$october+$november+$december;
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