One 、 The operator

 1. arithmetic operator

 2. Shift Operators

  The shift operator moves the binary digits

One int The memory occupied is 4 byte , so a The value of is expressed as ：

00000000 00000000 00000000 00000010

a Move one bit to the left , Auto add later 0,

00000000 00000000 00000000 00000100

Then convert the binary into decimal , That is to say 4

 3. Bit operators

 4. Assignment operator

=  +=  -=  *=  &=  ^=  |=  >>=  <<=

 5. Monocular operators

  Here is about ~ The operator Code for （ This involves the original code 、 Inverse code 、 Knowledge of complement ）

int main() {
    
	//0 The binary value of is 00000000 00000000 00000000 00000000
	//~ It's bitwise negation, so the result is 11111111 11111111 11111111 11111111
	// An integer stored in memory is a complement 
	//-1 The original code of is 10000000 00000000 00000000 00000001, The first digit represents the sign ,0 just 1 negative 
	// Inverse code is to reverse the original code , have to 11111111 11111111 11111111 11111110, The sign bits remain the same 
	// Complement is to add one to the inverse code , have to 11111111 11111111 11111111 11111111
	// The original and inverse complements of positive integers are the same 
	int a = 0;
	printf("~a The value of is :%d\n", ~a);
	return 0;
}

 6. Relational operator

 7. Logical operators

 8. Conditional operators （ ternary operators ）

   epx1 ? epx2 : exp3

int main() {
    
	// Conditional operator 
	int a = 1;
	int b = 3;
	int MAX = a>b ? a : b;
	printf("MAX:%d\n", MAX);
	return 0;
}

 9. Comma expression

Comma expression , A comma separates a string of expressions , The comma expression is evaluated once from left to right 、 The result of the entire expression is the result of the last expression .
   exp1, exp2, epx3, ...expN

 10. Subscript references and function calls

Two 、 Original code 、 Inverse code 、 Complement code

  In the computer , There are three ways to express signed numbers ： Original code 、 Inverse and complement ¹

  Original code 、 Inverse code 、 Complement is binary , The first digit is used to indicate positive and negative ,0 It means that this is a positive number ,1 Indicates that this is a negative number , The next number is used to indicate the size of this number . Usually, the 8 The multiples of are a set of , because 1B（ byte ）=8（bit） position , One bit represents a binary number . for instance ：

  The original code of a positive number 、 Inverse code 、 The complement is the same ;
  The inverse code of a negative number is that the original code is reversed except for the sign bit , Complement is based on the obtained inverse code +1.

Operator details ：【 Learning notes Dog learn C】 Explain operator