C Operator priority, operator priority

C Operator priority, operator priority

Priority	Operator	Name or meaning	Usage	Integration direction	Description
1	[]	Array subscript	Array name [constant expression]	Left to right
	()	Parentheses	(Expression)/function name (parameter table)
	.	Member selection (object)	Object. member name
	->	Member selection (pointer)	Object Pointer-> member name
2	-	Negative Operator	-Expression	Right to left	Single Object Operator
	(Type)	Forced type conversion	(Data Type) Expression
	++	Auto-increment operator	++ Variable name/variable name ++		Single Object Operator
	--	Auto-subtraction Operator	-- Variable name/variable name --		Single Object Operator
	*	Value Operator	* Pointer variable		Single Object Operator
	&	Bitwise operators	& Variable name		Single Object Operator
	!	Logical non-Operator	! Expression		Single Object Operator
	~	Bitwise Inverse Operator	~ Expression		Single Object Operator
	Sizeof	Length Operator	Sizeof (expression)
3	/	Division	Expressions/Expressions	Left to right	Binary Operators
	*	Multiplication	Expression * Expression		Binary Operators
	%	Remainder (Modulo)	Integer expression/Integer expression		Binary Operators
4	+	Add	Expression + expression	Left to right	Binary Operators
	-	Subtraction	Expression-expression		Binary Operators
5	<	Move left	Variable <expression	Left to right	Binary Operators
	>	Right Shift	Variable> Expression		Binary Operators
6	>	Greater	Expression> Expression	Left to right	Binary Operators
	> =	Greater than or equal	Expression> = expression		Binary Operators
	<	Less	Expression <expression		Binary Operators
	<=	Less than or equal	Expression <= expression		Binary Operators
7	=	Equal	Expression = expression	Left to right	Binary Operators
	! =	Not equal	Expression! = Expression		Binary Operators
8	&	Bitwise AND	Expressions & Expressions	Left to right	Binary Operators
9	^	Bitwise OR	Expression ^ expression	Left to right	Binary Operators
10	|	By bit or	Expression | expression	Left to right	Binary Operators
11	&&	Logic and	Expressions & Expressions	Left to right	Binary Operators
12	|	Logic or	Expression | expression	Left to right	Binary Operators
13	? :	Conditional Operators	Expression 1? Expression 2: expression 3	Right to left	Three-object Operator
14	=	Value assignment operator	Variable = expression	Right to left
	/=	Assignment After Division	Variable/= expression
	* =	Assign value after Multiplication	Variable * = expression
	% =	Assign value after modulo operation	Variable % = expression
	+ =	Add and assign values	Variable + = expression
	-=	Value after subtraction	Variable-= expression
	<=	Value after left shift	Variable <= expression
	>>=	Value after right shift	Variable> = expression
	& =	Bitwise AND postvalue	Variable & = expression
	^ =	Value Based on bitwise XOR	Variable ^ = expression
	| =	Value by bit or after	Variable | = expression
15	,	Comma Operator	Expressions, expressions ,...	Left to right	Sequential operation from left to right

 

 

Note:

For operators with the same priority, the operation order is determined by the combination direction.

 

 ! > Arithmetic Operators> Relational operators >&>||> value assignment operators

 

Among all priorities, only three are combined from right to left. They are single object operators, condition operators, and value assignment operators. All others are from left to right.

 

Note that ++ and -- are right combinations. Therefore, the combination of ++ a ++ is equivalent to ++ (a ++). Of course, a ++ is a left value, so this expression is incorrect.

 

In C, only four operators specify the operation direction. They are &, |, conditional operators, and value assignment operators.
&, | The value of the Left expression is calculated first. When the value of the Left expression can determine the value of the entire expression, the value of the right expression is no longer calculated. For example, if a = 0 & B; & the left digit of the operator is 0, expression B on the right is no longer judged.
In the conditional operators. Such as? B: c; first judge the value of a, and then evaluate one of B or c based on the value of.
The value assignment expression requires that the expression on the right be evaluated first, so that a = B = c = 6; is possible.