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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
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Type
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Size (in bits)
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Range
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|
sbyte
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8
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-128 to 127
|
|
byte
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8
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0 to 255
|
|
short
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16
|
-32768 to 32767
|
|
ushort
|
16
|
0 to 65535
|
|
int
|
32
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-2147483648 to 2147483647
|
|
uint
|
32
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0 to 4294967295
|
|
long
|
64
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-9223372036854775808 to 9223372036854775807
|
|
ulong
|
64
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0 to 18446744073709551615
|
|
char
|
16
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0 to 65535
|
- Floating Point
- Decimal
The Floating Point and Decimal Types with Size, precision, and Range
|
Type
|
Size (in bits)
|
precision
|
Range
|
|
float
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32
|
7 digits
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1.5 x 10-45 to 3.4 x 1038
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|
double
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64
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15-16 digits
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5.0 x 10-324 to 1.7 x 10308
|
|
decimal
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128
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28-29 decimal places
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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
在 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
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+ - ! ~ ++x --x (T)x
|
left
|
|
Multiplicative
|
* / %
|
left
|
|
Additive
|
+ -
|
left
|
|
Shift
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<< >>
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left
|
|
Relational
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< > <= >= is as
|
left
|
|
Equality
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== !=
|
right
|
|
Logical AND
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&
|
left
|
|
Logical XOR
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^
|
left
|
|
Logical OR
|
|
|
left
|
|
Conditional AND
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&&
|
left
|
|
Conditional OR
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||
|
left
|
|
Null Coalescing
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??
|
left
|
|
Ternary
|
?:
|
right
|
|
Assignment
|
= *= /= %= += -= <<= >>= &= ^= |= =>
|
right
|
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