Arithmetic expressions using binary operators

AWK supports almost all basic arithmetic operators for building arithmetic expressions.These operators are binary operators; that is, they operate on two variables and are very similar to C language expressions.All these arithmetic operators follow the normal precedence rule.AWK supports the following arithmetic operators.

Addition (p + q):

This is represented by a plus (+) symbol, which adds two or more numbers. These numbers could be variablesor constants.For example, we can add two numbers after assigning them to two variables as follows:

$ awk 'BEGIN{ p = 20; q = 30; print "( p + q ) = ",( p + q )}'

The output on execution of this code is as follows:

( p + q ) =  50

Now, we will use the marks.txt sample file to calculate the sum of marks obtained by a student using the arithmetic operator, as follows:

$ vi sum.awk

BEGIN    {
    printf "%-6s\t%-7s\t%-7s\t%-7s\t%-7s\t%-7s\t%-5s\n", "Name", "Eng","Hindi","Maths","Science","Arts","Total"
    }
  ...