Unary expressions

An operator that accepts a single operand is called a unary operator, and expressions built using unary operator are called unary expressions.Increment and decrement operators also fall under this category.

Unary plus:

It is represented by a singleplus (+) symbol. It multiplies a single operand by +1. In the following example, we assign a variablep with value -5.On applying the unary plus operator to the variable, it multiplies the variable p with +1 and again stores the result inside p, as follows:

$ awk 'BEGIN{ p = -5; p = +p; print "p = ",p }' 

The output on execution of the preceding code is as follows:

p =  -5

Unary minus:

It is represented by a single minus(-) symbol. It multiplies a single operand by -1. In the following example, we assign a variablep with value -5.On applying the unaryminusoperator, it multiplies the variable p by -1 and again stores the result inside p:

$ awk 'BEGIN{ p = -5; p = -p; print "p = ",p }' 

The output on execution of the preceding code is as...