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[Bash] Two Variable Exponentiation

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Top Forums Shell Programming and Scripting [Bash] Two Variable Exponentiation
# 1  
Old 08-17-2011
[Bash] Two Variable Exponentiation
Hey Unixians.

There exist two variables with arbitrary (though numeric) values:
Code:
$variable1 , $variable2


Attemping to perform the '**' operator prints the string rather than performs the operation:
Code:
echo $variable1 ** $variable2

How do I amend my code?
Thanks in advance.

Bash version 4.2.8; if I recall correctly the ** operator was added around version two, so I should be up to date.
# 2  
Old 08-17-2011
Code:
$ var1=10
$ var2=2
$ echo $(( var1 ** var2 ))
100

# 3  
Old 08-17-2011
Thanks chief, works like a charm. I didn't think to group them, but lesson learned.
# 4  
Old 08-17-2011
Quote:
Originally Posted by SyntaxKite
Thanks chief, works like a charm. I didn't think to group them, but lesson learned.
It's not just grouping them as you would group a mathematical expression with parentheses or brackets, its a special construct for arithmetic testing.

See here for more on the issue: The Double-Parentheses Construct
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