Operators
Category | Operator |
|---|---|
Arithmetic | + – * / % |
Logical | & | ^ ~ && || ! |
String concatenation | + |
Increment and decrement | ++ — |
Bit shifting | << >> |
Comparison | == != < > <= >= |
Assignment | = += -= *= /= %= &= |= ^= <<= >>= |
Member access (for objects and structs) | . |
Indexing (for arrays and indexers) | [] |
Cast | () |
Conditional (the Ternary Operator) | ?: |
Object Creation | new |
Type information | sizeof (unsafe code only) is typeof as |
Overflow exception control | checked unchecked |
Indirection and Address | * –> & (unsafe code only) [] |
Câu sau đây có nghĩa là x bằng với 3:
x = 3;
Nếu chúng ta muốn so sánh x với một giá trị chúng ta sử dụng kí hiệu sau ==:
if (x == 3)
Operator Shortcuts
Bảng dưới đây trình bày một danh sách đầy đủ của shortcut operators có giá trị trong C#:
Shortcut Operator | Tương đương |
|---|---|
x++, ++x | x = x + 1 |
x–, –x | x = x – 1 |
x += y | x = x + y |
x -= y | x = x – y |
x *= y | x = x * y |
x /= y | x = x / y |
x %= y | x = x % y |
x >>= y | x = x >> y |
x <<= y | x = x << y |
x &= y | x = x & y |
x |= y | x = x | y |
x ^= y | x = x ^ y |
Thí dụ :
int x = 5;
if (++x == 6)
{
Console.WriteLine(“This will execute”);
}
if (x++ == 7)
{
Console.WriteLine(“This won’t”);
}
x += 5;
x = x + 5;
The Ternary Operator
Cú pháp :
condition ? true_value : false_value
Thí dụ :
int x = 1;
string s = x.ToString() + ” “;
s += (x == 1 ? “man” : “men”);
Console.WriteLine(s);
is
int i = 10;
if (i is object)
{
Console.WriteLine(“i is an object”);
}
sizeof
string s = “A string”;
unsafe
{
Console.WriteLine(sizeof(int));
}
Operator Precedence
Group | Operators |
|---|---|
() . [] x++ x– new typeof sizeof checked unchecked | |
Unary | + – ! ~ ++x –x and casts |
Multiplication/Division | * / % |
Addition/Subtraction | + – |
Bitwise shift operators | << >> |
Relational | < > <= >= is as |
Comparison | == != |
Bitwise AND | & |
Bitwise XOR | ^ |
Bitwise OR | | |
Boolean AND | && |
Boolean OR | || |
Ternary operator | ?: |
Assignment | = += -= *= /= %= &= |= ^= <<= >>= >>>= |
