C operators

Arithmetic operators

The following table shows all the arithmetic operators supported by C language. Assume that the value of variable A is 10 and the value of variable B is 20, then:

##Operator DescriptionExample+Add the two operandsA + B will get 30- Subtracting the second operand from the first operand A - B will give -10*Multiply the two operandsA * B will get 200/numerator Dividing by the denominator B / A will get 2%modulo operator, the remainder after integer divisionB % A will get 0++ auto-increment operator, the integer value is increased by 1A++ will get 11-- Decrement operator, decrement the integer value by 1A-- will get 9

Example

Please look at the following example to learn about all the arithmetic operators available in C language:

#include <stdio.h>main(){   int a = 21;   int b = 10;   int c ;

   c = a + b;
   printf("Line 1 - c 的值是 %d\n", c );
   c = a - b;
   printf("Line 2 - c 的值是 %d\n", c );
   c = a * b;
   printf("Line 3 - c 的值是 %d\n", c );
   c = a / b;
   printf("Line 4 - c 的值是 %d\n", c );
   c = a % b;
   printf("Line 5 - c 的值是 %d\n", c );
   c = a++; 
   printf("Line 6 - c 的值是 %d\n", c );
   c = a--; 
   printf("Line 7 - c 的值是 %d\n", c );}

When the above code is compiled and executed, it will produce the following results:

Line 1 - c 的值是 31Line 2 - c 的值是 11Line 3 - c 的值是 210Line 4 - c 的值是 2Line 5 - c 的值是 1Line 6 - c 的值是 21Line 7 - c 的值是 22

Relational operators

The following table shows all the relational operators supported by C language. Assume that the value of variable A is 10 and the value of variable B is 20, then:

##Operator DescriptionExample==Checks whether the values ​​of the two operands are equal. If they are equal, the condition is true. (A == B) is not true. != Checks whether the values ​​of the two operands are equal. If they are not equal, the condition is true. (A != B) is true. >Checks whether the value of the left operand is greater than the value of the right operand, if so, the condition is true. (A > B) is not true. <Checks whether the value of the left operand is less than the value of the right operand, if so the condition is true. (A < B) is true. >=Checks whether the value of the left operand is greater than or equal to the value of the right operand, if so the condition is true. (A >= B) is not true. <=Checks whether the value of the left operand is less than or equal to the value of the right operand, if so the condition is true. (A <= B) is true. Example

Please look at the following example to learn about all the relational operators available in C language:

#include <stdio.h>main(){   int a = 21;   int b = 10;   int c ;   if( a == b )   {
      printf("Line 1 - a 等于 b\n" );   }   else   {
      printf("Line 1 - a 不等于 b\n" );   }   if ( a < b )   {
      printf("Line 2 - a 小于 b\n" );   }   else   {
      printf("Line 2 - a 不小于 b\n" );   }   if ( a > b )   {
      printf("Line 3 - a 大于 b\n" );   }   else   {
      printf("Line 3 - a 不大于 b\n" );   }   /* 改变 a 和 b 的值 */
   a = 5;
   b = 20;   if ( a <= b )   {
      printf("Line 4 - a 小于或等于 b\n" );   }   if ( b >= a )   {
      printf("Line 5 - b 大于或等于 b\n" );   }}

When the above code When compiled and executed, it produces the following results:

Line 1 - a 不等于 bLine 2 - a 不小于 bLine 3 - a 大于 bLine 4 - a 小于或等于 bLine 5 - b 大于或等于 b

Logical operators

The following table shows all the relational logical operators supported by the C language. Assume that the value of variable

A is 1 and the value of variable B is 0, then:

Operator DescriptionInstance&& is called the logical AND operator. The condition is true if both operands are non-zero. (A && B) is false. || is called the logical OR operator. The condition is true if either of the two operands is non-zero. (A || B) is true. ! is called the logical NOT operator. Used to reverse the logical state of the operand. The logical NOT operator will make the condition false if it is true. !(A && B) is true.

Example

Please look at the following example to learn about all the logical operators available in C language:

#include <stdio.h>main(){   int a = 5;   int b = 20;   int c ;   if ( a && b )   {
      printf("Line 1 - 条件为真\n" );   }   if ( a || b )   {
      printf("Line 2 - 条件为真\n" );   }   /* 改变 a 和 b 的值 */
   a = 0;
   b = 10;   if ( a && b )   {
      printf("Line 3 - 条件为真\n" );   }   else   {
      printf("Line 3 - 条件不为真\n" );   }   if ( !(a && b) )   {
      printf("Line 4 - 条件为真\n" );   }}

When the above code is compiled and executed, it will produce the following results:

Line 1 - 条件为真Line 2 - 条件为真Line 3 - 条件不为真Line 4 - 条件为真

Bitwise operators

Bitwise operators act on bits and perform operations bit by bit. The truth table for &, | and ^ is as follows:

p	q	p & q	p | q	p ^ q
0	0	0	0	0
0	1	0	1	1
1	1	1	1	0
1	0	0	1	1

## Suppose if A = 60, and B = 13, now represented in binary format, they look like this:

A = 0011 1100

B = 0000 1101

---------- -------

A&B = 0000 1100

A|B = 0011 1101

A^B = 0011 0001

~A = 1100 0011

The following table shows the bit operators supported by C language. Assume that the value of variable

A is 60 and the value of variable B is 13, then:

##Operator&|^~<<##>>Binary right shift operator. The value of the left operand is shifted to the right by the number of bits specified by the right operand. A >> 2 will get 15, which is 0000 1111

Example

Please look at the following example to learn about all the bitwise operators available in C language:

#include <stdio.h>main(){   unsigned int a = 60;/* 60 = 0011 1100 */  
   unsigned int b = 13;/* 13 = 0000 1101 */   int c = 0;           

   c = a & b;       /* 12 = 0000 1100 */ 
   printf("Line 1 - c 的值是 %d\n", c );

   c = a | b;       /* 61 = 0011 1101 */
   printf("Line 2 - c 的值是 %d\n", c );

   c = a ^ b;       /* 49 = 0011 0001 */
   printf("Line 3 - c 的值是 %d\n", c );

   c = ~a;          /*-61 = 1100 0011 */
   printf("Line 4 - c 的值是 %d\n", c );

   c = a << 2;     /* 240 = 1111 0000 */
   printf("Line 5 - c 的值是 %d\n", c );

   c = a >> 2;     /* 15 = 0000 1111 */
   printf("Line 6 - c 的值是 %d\n", c );}

When the above code is compiled and executed, it will produce the following results:

Line 1 - c 的值是 12Line 2 - c 的值是 61Line 3 - c 的值是 49Line 4 - c 的值是 -61Line 5 - c 的值是 240Line 6 - c 的值是 15

Assignment operators

The following table lists the assignment operators supported by C language:

Description	Example
The binary AND operator copies one bit to the result if both operands are present at the same time.	(A & B) will get 12, which is 0000 1100
If present in any operand, binary OR operation character is copied into the result.	(A | B) will get 61, which is 0011 1101
if present in one of the operands but not both The binary XOR operator copies one of the two operands into the result.	(A ^ B) will get 49, which is 0011 0001
The two's complement operator is a unary operator with " Flip" bit effect.	(~A ) will get -61, which is 1100 0011, 2's complement, signed binary number.
Binary left shift operator. The value of the left operand is shifted left by the number of bits specified by the right operand.	A << 2 will get 240, which is 1111 0000

##*=Multiplication and assignment operator, assigns the result of multiplying the right operand by the left operand to the left operand C *= A is equivalent to C = C * A/=The division and assignment operator assigns the result of dividing the left operand by the right operand to the left operandC /= A is equivalent to C = C / A%=Modulo and assignment operator, find the modulus of two operands and assign the value to the left operandC %= A is equivalent to C = C % A<<=left shift and assignment operatorC <<= 2 is equivalent to C = C << 2>>=Right shift and assignment operatorC >>= 2 is equivalent to C = C >> 2##&=^=|=Example

Operator	Description	Example
=	Simple assignment operator, assigns the value of the right operand to the left operand	C = A + B will assign the value of A + B to C
+=	addition and assignment operator, adding the right operand to the left operation The result of the number is assigned to the left operand	C += A, which is equivalent to C = C + A
-=	subtraction and assignment operator, Assign the result of subtracting the right operand from the left operand to the left operand	C -= A which is equivalent to C = C - A
bitwise AND and assignment operator	C &= 2 is equivalent to C = C & 2
Bitwise XOR and assignment operator	C ^= 2 is equivalent to C = C ^ 2
Bitwise OR and assignment operator	C |= 2 is equivalent to C = C | 2

Please look at the following example to learn about all the assignment operators available in C language:

#include <stdio.h>main(){   int a = 21;   int c ;

   c =  a;
   printf("Line 1 - =  运算符实例，c 的值 = %d\n", c );

   c +=  a;
   printf("Line 2 - += 运算符实例，c 的值 = %d\n", c );

   c -=  a;
   printf("Line 3 - -= 运算符实例，c 的值 = %d\n", c );

   c *=  a;
   printf("Line 4 - *= 运算符实例，c 的值 = %d\n", c );

   c /=  a;
   printf("Line 5 - /= 运算符实例，c 的值 = %d\n", c );

   c  = 200;
   c %=  a;
   printf("Line 6 - %= 运算符实例，c 的值 = %d\n", c );

   c <<=  2;
   printf("Line 7 - <<= 运算符实例，c 的值 = %d\n", c );

   c >>=  2;
   printf("Line 8 - >>= 运算符实例，c 的值 = %d\n", c );

   c &=  2;
   printf("Line 9 - &= 运算符实例，c 的值 = %d\n", c );

   c ^=  2;
   printf("Line 10 - ^= 运算符实例，c 的值 = %d\n", c );

   c |=  2;
   printf("Line 11 - |= 运算符实例，c 的值 = %d\n", c );}

When the above code is compiled and executed, it will produce the following Result:

Line 1 - =  运算符实例，c 的值 = 21Line 2 - += 运算符实例，c 的值 = 42Line 3 - -= 运算符实例，c 的值 = 21Line 4 - *= 运算符实例，c 的值 = 441Line 5 - /= 运算符实例，c 的值 = 21Line 6 - %= 运算符实例，c 的值 = 11Line 7 - <<= 运算符实例，c 的值 = 44Line 8 - >>= 运算符实例，c 的值 = 11Line 9 - &= 运算符实例，c 的值 = 2Line 10 - ^= 运算符实例，c 的值 = 0Line 11 - |= 运算符实例，c 的值 = 2

Miscellaneous operators ↦ sizeof & ternary

The following table lists some other important operators supported by the C language, including

sizeof

and ?:.

Operatorsizeof()&*? :

Example

Look at the following example to see all the miscellaneous operators available in C language:

#include <stdio.h>main(){   int a = 4;   short b;   double c;   int* ptr;   /* sizeof 运算符实例 */
   printf("Line 1 - 变量 a 的大小 = %d\n", sizeof(a) );
   printf("Line 2 - 变量 b 的大小 = %d\n", sizeof(b) );
   printf("Line 3 - 变量 c 的大小 = %d\n", sizeof(c) );   /* & 和 * 运算符实例 */
   ptr = &a;/* 'ptr' 现在包含 'a' 的地址 */
   printf("a 的值是 %d\n", a);
   printf("*ptr 是 %d\n", *ptr);   /* 三元运算符实例 */
   a = 10;
   b = (a == 1) ? 20: 30;
   printf( "b 的值是 %d\n", b );

   b = (a == 10) ? 20: 30;
   printf( "b 的值是 %d\n", b );}

When the above code is compiled and executed, it produces the following results:

a 的值是 4*ptr 是 4b 的值是 30b 的值是 20

Operator precedence in C

The precedence of an operator determines the combination of terms in an expression. This affects how an expression is evaluated. Some operators have higher precedence than others, for example, multiplication and division operators have higher precedence than addition and subtraction operators.

For example x = 7 + 3 * 2, here, x is assigned the value 13 instead of 20, because the operator * has a higher priority than +, so the multiplication 3*2 is calculated first, and then Plus 7 more.

The following table lists each operator according to operator priority from high to low. Operators with higher priority appear at the top of the table, and operators with lower priority appear at the bottom of the table. under. In an expression, operators with higher precedence are evaluated first.

Description	Instance
Return the size of the variable.	sizeof(a) will return 4, where a is an integer.
Returns the address of the variable.	&a; will give the actual address of the variable.
points to a variable.	*a; will point to a variable.
Conditional expression	If the condition is true? then the value is X: otherwise the value is Y

Category	Operator	Associativity
Suffix	() [] -> . ++ - -	From left to right
One yuan	+ - ! ~ ++ - - (type)* & sizeof	From right to left
Multiplication and division	* / %	From left to right
Addition and subtraction	+ -	From left to right
Shift	<< >>	From left to right
Relationship	< <= > >=	From left to right
Equal	== !=	From left to right
Bit AND AND	&	From left to right
Bit XOR XOR	^	Left to right
bit OR	|	Left to right
Logic AND	&&	from left to right
logical OR	||	from left To the right
Condition	?:	From right to left
Assignment	= += -= *= /= %=>>= <<= &= ^= |=	From right to left
comma	,	From left to right

Example

Please look at the following example to understand C language Priority of operators in:

#include <stdio.h>main(){   int a = 20;   int b = 10;   int c = 15;   int d = 5;   int e;
 
   e = (a + b) * c / d;      // ( 30 * 15 ) / 5
   printf("(a + b) * c / d 的值是 %d\n",  e );

   e = ((a + b) * c) / d;    // (30 * 15 ) / 5
   printf("((a + b) * c) / d 的值是 %d\n" ,  e );

   e = (a + b) * (c / d);   // (30) * (15/5)
   printf("(a + b) * (c / d) 的值是 %d\n",  e );

   e = a + (b * c) / d;     //  20 + (150/5)
   printf("a + (b * c) / d 的值是 %d\n" ,  e );  
   return 0;}

When the above code is compiled and executed, it produces the following results:

(a + b) * c / d 的值是 90((a + b) * c) / d 的值是 90(a + b) * (c / d) 的值是 90a + (b * c) / d 的值是 50