The unary indirection operator (*) “dereferences” a pointer; that is, it converts a pointer value to an l-value. The operand of the indirection operator must be a pointer to a type. The result of the indirection expression is the type from which the pointer type is derived. The use of the * operator in this context is different from its meaning as a binary operator, which is multiplication.
If the operand points to a function, the result is a function designator. If it points to a storage location, the result is an l-value designating the storage location.
If the pointer value is invalid, the result is undefined. The following list includes some of the most common conditions that invalidate a pointer value.