About unary operators

Unary operators take one operand. The increment (++) and decrement (--) operators in this group are prefix operators, which means that they appear before the operand in an expression. They can also appear after the operand, in which case they are postfix operators. For information on postfix operators, see About postfix operators.

The prefix operators differ from the postfix counterparts because the increment or decrement operation completes before the value of the overall expression is returned. For example, the following code shows how the value of the expression xNum++ is returned after the value is incremented.

var xNum:Number = 0;
trace(++xNum); // 1
trace(xNum); // 1

All of the operators in this table have equal precedence:

Operator	Operation performed
`++`	Increment (prefix)
`--`	Decrement (prefix)
`+`	Unary +
`!`	Unary - (negation)
`typeof`	Returns type information
`void`	Returns undefined value

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