本文主要介紹C#的Operators、Types和Variables,以供有興趣的朋友參考。


Variables
C# 是強型別語言,因此每一個變數和物件都必須有宣告的型別。
 
Types
C#內建的基礎型別有:
* Boolean Type - true and false
* numeric types
- Integrals
The Size and Range of C# Integral Types
Type
Size (in bits)
Range
sbyte
8
-128 to 127
byte
8
0 to 255
short
16
-32768 to 32767
ushort
16
0 to 65535
int
32
-2147483648 to 2147483647
uint
32
0 to 4294967295
long
64
-9223372036854775808 to 9223372036854775807
ulong
64
0 to 18446744073709551615
char
16
0 to 65535
 
- Floating Point
- Decimal
The Floating Point and Decimal Types with Size, precision, and Range
Type
Size (in bits)
precision
Range
float
32
7 digits
1.5 x 10-45 to 3.4 x 1038
double
64
15-16 digits
5.0 x 10-324 to 1.7 x 10308
decimal
128
28-29 decimal places
1.0 x 10-28 to 7.9 x 1028
 
*String - is a sequence of text characters.
字串物件是不變的,表示一旦建立就無法變更。修改字串會有新字串物件的建立,所以基於效能的考量,必須使用 StringBuilder  類別執行大量的串連或其他所需的字串管理,以後再做更詳細的介紹
C# Character Escape Sequences
Escape Sequence
Meaning
\'
Single Quote
\"
Double Quote
\\
Backslash
\0
Null, not the same as the C# null value
\a
Bell
\b
Backspace
\f
form Feed
\n
Newline
\r
Carriage Return
\t
Horizontal Tab
\v
Vertical Tab
 
Operators
C# 中,運算子是條件或符號,需要以一或多個運算式 (稱為運算元) 做為輸入並傳回值。
Operators with their precedence and Associativity
Category (by precedence)
Operator(s)
Associativity
Primary
x.y  f(x)  a[x]  x++  x--  new  typeof  default  checked  unchecked delegate
left
Unary
+  -  !  ~  ++x  --x  (T)x
left
Multiplicative
*  /  %
left
Additive
+  -
left
Shift
<<  >>
left
Relational
<  >  <=  >=  is as
left
Equality
==  !=
right
Logical AND
&
left
Logical XOR
^
left
Logical OR
|
left
Conditional AND
&&
left
Conditional OR
||
left
Null Coalescing
??
left
Ternary
?:
right
Assignment
=  *=  /=  %=  +=  -=  <<=  >>=  &=  ^=  |=  =>
right
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