第 3 章 變數、資料 型別與運算子

3 Ren-Jie Wang, , Ph.D. [email protected] http://rjwang.myweb.hinet.net

3 3-1 3-2 3-3 3-4 3-5

3-1 -Variables

3-2-1 Visual Basic-Visual Basic(VB)"_"16383abcABC.+-*/^

3-2-1 Visual Basic-Visual Basicdef, no_123, size1, _123, _abc Car, count, height, s1, s2 _ , 123abc

3-2-1 Visual Basic-3

Boolean

bln

blnDoit

Char

chr

chrA

Integer

int

intCounter

Object

obj

objCar

String

str

strName

3-2-1 Visual Basic- CamelCasingCamelCasing1/

"_"

MAX_SIZEPI

22

sizeuserName

/

2

pressButtonscrollScreen

3-2-2 -Visual BasicDimDim volumnvolumnObjectAsDim height, width As Integer2Dim name As String, depth As Integer

3-2-2 -Dim name As String, depth = 100Dim title As String = "Visual Basic"nametitletitledepth1002008

3-2-6 Enumeration-EnumerationsEnum/End EnumEnum Color As Integer White = 1 Red Blue = 5 Green Black = GreenEnd Enum

3-3

3-3-1 Visual Basic

3-3-2 -

19

19

&O377

255

&Hff

255

&H3E7

999

3-3-4 Boolean TypeTrueFalse

3-3-6 Char TypeUnicodeUnsigned16Visual BasicCharacter LiteralsDim a As Char = "A"C

3-3-5 String0String LiteralsDim str1 As String = Visual BasicDim str2 As String = Hello World!Dim str3 As String = _ \\localhost\download\joe

3-3-7 //"#"Dim tday As Date = #12/30/2012 12:00:00 AM#/41224AMPM240

3-4-3 -f = X^2-2*X+3f = (X+Y)^2+5FahrenheitCelsiusF = (9.0 * C) / 5.0 + 32.0C = (5.0 / 9.0 ) * (F - 32)

3-4-4 Like-StringVisual Basic

&"abc" & "de" = "abcde"LikeTrueFalse

3-4-5 "="

=

x = y

N/A

^=

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

3-5-1 -Implicit Conversions

"250" + 125

375

"250" & 125

"250125"

"250" + "125"

"250125"