Csharp 简明教程

A&B = 0000 1100

A|B = 0011 1101

A^B = 0011 0001

~A  = 1100 0011

The Bitwise operators supported by C# are listed in the following table. Assume variable A holds 60 and variable B holds 13, then −

link:../csharp/csharp_bitwise_operators.html[Show Examples]
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|Operator|Description|Example
|&|Binary AND Operator copies a bit to the result if it exists in both operands.|(A & B) = 12, which is 0000 1100
|||Binary OR Operator copies a bit if it exists in either operand.|(A | B) = 61, which is 0011 1101
|^|Binary XOR Operator copies the bit if it is set in one operand but not both.|(A ^ B) = 49, which is 0011 0001
|~|Binary Ones Complement Operator is unary and has the effect of 'flipping' bits.|(~A ) = -61, which is 1100 0011 in 2's complement due to a signed binary number.
|<<|Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand.|A << 2 = 240, which is 1111 0000
|>>|Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand.|A >> 2 = 15, which is 0000 1111
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=== Assignment Operators

There are following assignment operators supported by C# −

link:../csharp/csharp_assignment_operators.html[Show Examples]
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|Operator|Description|Example
|=|Simple assignment operator, Assigns values from right side operands to left side operand|C = A + B assigns value of A + B into C
|+=|Add AND assignment operator, It adds right operand to the left operand and assign the result to left operand|C += A is equivalent to C = C + A
|-=|Subtract AND assignment operator, It subtracts right operand from the left operand and assign the result to left operand|C -= A is equivalent to C = C - A
|*=|Multiply AND assignment operator, It multiplies right operand with the left operand and assign the result to left operand|C *= A is equivalent to C = C * A
|/=|Divide AND assignment operator, It divides left operand with the right operand and assign the result to left operand|C /= A is equivalent to C = C / A
|%=|Modulus AND assignment operator, It takes modulus using two operands and assign the result to left operand|C %= A is equivalent to C = C % A
|<<=|Left shift AND assignment operator|C <<= 2 is same as C = C << 2
|>>=|Right shift AND assignment operator|C >>= 2 is same as C = C >> 2
|&=|Bitwise AND assignment operator|C &= 2 is same as C = C & 2
|^=|bitwise exclusive OR and assignment operator|C ^= 2 is same as C = C ^ 2
||=|bitwise inclusive OR and assignment operator|C |= 2 is same as C = C | 2
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=== Miscellaneous Operators

There are few other important operators including *sizeof, typeof* and *? :* supported by C#.

link:../csharp/csharp_misc_operators.html[Show Examples]
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|Operator|Description|Example
|sizeof()|Returns the size of a data type.|sizeof(int), returns 4.
|typeof()|Returns the type of a class.|typeof(StreamReader);
|&|Returns the address of an variable.|&a; returns actual address of the variable.
|*|Pointer to a variable.|*a; creates pointer named 'a' to a variable.
|? :|Conditional Expression|If Condition is true ? Then value X : Otherwise value Y
|is|Determines whether an object is of a certain type.|If( Ford is Car) // checks if Ford is an object of the Car class.
|as|Cast without raising an exception if the cast fails.|Object obj = new StringReader("Hello"); StringReader r = obj as StringReader;

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=== Operator Precedence in C

Operator precedence determines the grouping of terms in an expression. This affects evaluation of an expression. Certain operators have higher precedence than others; for example, the multiplication operator has higher precedence than the addition operator.

For example x = 7 + 3 * 2; here, x is assigned 13, not 20 because operator * has higher precedence than +, so the first evaluation takes place for 3*2 and then 7 is added into it.

Here, operators with the highest precedence appear at the top of the table, those with the lowest appear at the bottom. Within an expression, higher precedence operators are evaluated first.

link:../csharp/csharp_operators_precedence.html[Show Examples]
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|Category|Operator|Associativity
|Postfix|() [] -> . ++ - -|Left to right
|Unary|+ - ! ~ ++ - - (type)* & sizeof|Right to left
|Multiplicative|* / %|Left to right
|Additive|+ -|Left to right
|Shift|<< >>|Left to right
|Relational|< <= > >=|Left to right
|Equality|== !=|Left to right
|Bitwise AND|&|Left to right
|Bitwise XOR|^|Left to right
|Bitwise OR|||Left to right
|Logical AND|&&|Left to right
|Logical OR||||Left to right
|Conditional|?:|Right to left
|Assignment|= += -= *= /= %=>>= <<= &= ^= |=|Right to left
|Comma|,|Left to right
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