Q.What the following sign ‘--’ represents?

Beyond the basic arithmetic and relational operators, C offers several operators that make code shorter and more expressive.

Assignment and compound-assignment operators. The simple = stores a value in a variable. C also provides compound forms that combine an operation with assignment: +=, -=, *=, /=, %= and the bitwise ones such as ^=. For example, x += y is a compact way of writing x = x + y, and x ^= y means x = x ^ y. These give a neat, compact representation of arithmetic and bit operations.

Increment and decrement operators. The increment operator ++ adds 1 to a variable and the decrement operator -- subtracts 1. Each has two forms: the prefix form (++a) changes the value before it is used in the expression, while the postfix form (a++) uses the current value first and changes it afterwards. …