Expressions with Unary Operators

Unary operators act on only one operand in an expression. The unary operators are:

• Indirection operator (*)

• Address-of operator (&)

• Unary plus operator ()

• Unary negation operator (–)

• Logical negation operator (!)

• One's complement operator (~)

• Prefix increment operator (+)

• Prefix decrement operator (––)

• Cast Operator ()

• sizeof operator

• __uuidof operator

• __alignof operator

• new operator

• delete operator

These operators have right-to-left associativity. Unary expressions generally involve syntax that precedes a postfix or primary expression.

The following are the possible forms of unary expressions:

postfix-expression 
++unary-expression 
––unary-expression 
unary-operator cast-expression 
sizeof .unary-expression 
sizeof ( type-name ) 
allocation-expression 
deallocation-expression

The unary-operator may be one of

* & + – ! ~

Any postfix expression is considered a unary expression, and since any primary expression is considered a postfix expression, all primary expressions are considered unary expressions as well. For more information, see Postfix Expressions and Primary Expressions.

The allocation-expression refers to the new operator. The deallocation-expression refers to the delete operator. See the links above.

The cast-expression is a unary expression with an optional cast to alter the type. For more information see Cast Operator: ().

See Also

Reference

Types of Expressions