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The `awk`

language uses the common arithmetic operators when
evaluating expressions. All of these arithmetic operators follow normal
precedence rules and work as you would expect them to.

The following example uses a file named `grades`, which contains
a list of student names as well as three test scores per student (it’s
a small class):

Pat 100 97 58 Sandy 84 72 93 Chris 72 92 89

This program takes the file `grades` and prints the average
of the scores:

$awk '{ sum = $2 + $3 + $4 ; avg = sum / 3>print $1, avg }' grades-| Pat 85 -| Sandy 83 -| Chris 84.3333

The following list provides the arithmetic operators in `awk`

,
in order from the highest precedence to the lowest:

`x`^`y``x`**`y`Exponentiation;

`x`raised to the`y`power. ‘`2 ^ 3`’ has the value eight; the character sequence ‘`**`’ is equivalent to ‘`^`’. (c.e.)`-`

`x`Negation.

`+`

`x`Unary plus; the expression is converted to a number.

`x`*`y`Multiplication.

`x`/`y`Division; because all numbers in

`awk`

are floating-point numbers, the result is*not*rounded to an integer—‘`3 / 4`’ has the value 0.75. (It is a common mistake, especially for C programmers, to forget that*all*numbers in`awk`

are floating-point, and that division of integer-looking constants produces a real number, not an integer.)`x`%`y`Remainder; further discussion is provided in the text, just after this list.

`x`+`y`Addition.

`x`-`y`Subtraction.

Unary plus and minus have the same precedence, the multiplication operators all have the same precedence, and addition and subtraction have the same precedence.

When computing the remainder of ‘` x % y`’,
the quotient is rounded toward zero to an integer and
multiplied by

b * int(a / b) + (a % b) == a

One possibly undesirable effect of this definition of remainder is that

is negative if `x` % `y``x` is negative. Thus:

-17 % 8 = -1

In other `awk`

implementations, the signedness of the remainder
may be machine-dependent.

NOTE:The POSIX standard only specifies the use of ‘^’ for exponentiation. For maximum portability, do not use the ‘**’ operator.

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