QTP-14 VBScript VBS基礎

1.     熟練掌握下面的方法：

Strings:

Lcase() & Ucase()      ‘大小寫 strComp()         StrReverse()          ‘倒序 Len() Left() Right() Mid() InStr() InStrRev                       ‘倒序搜尋 LTrim(), RTrim(), Trim() Replace() Space()                       ‘産生空格 String(3,”A”)                       ‘産生給定字母”AAA”

Array:

Join Split Filter                              ‘傳回含有特定字元串的數組元素

Conversion function

CBool, CByte, CCur, CDate, CInt, CLng, CSng, CStr Asc():Returns the ANSI character code to the first letter in a string Chr():Returns the character associated with the specified ANSI character code. Hex/Oct: converts a number to its Hexadecimal or Octal string

Date and Time functions:

Date() Time() Now() Day/Month/Year Hour/Minute/Seconds Weekday          ‘傳回一周的第幾天（7天制） DataDiff            ‘兩個日期相差的天數 Timer                ‘計時（一天内）

Others

Escape/ UnEscape Escape : Encodes a string so it contains only ASCII characters. UnEscape :Decodes a string encoded with the Escape function. TypeName：Returns Variant subtype information about a variable. TypeName(4)            ' Returns "Integer". VarType: Returns a value indicating the subtype of a variable. MyCheck = VarType(#10/19/62#)   ' Returns 7. GetRef: Returns a reference to a procedure that can be bound to an event. Set object.eventname = GetRef(procname) CreateObject: Creates and returns a reference to an Automation object. CreateObject(servername.typename [, location]) GetObject: Returns a reference to an Automation object from a file. GetObject([pathname] [, class]) UBound / LBound Returns the largest / smallest available subscript for the indicated dimension of an array. Eval Evaluates an expression and returns the result. E.g. Eval("2=3")

2.     How to clear new line, line feeds, and tab etc.whitespace characters in a string?

'This function clear new line, line feeds,tab ect. whitespace characters Function CleanText (s_Text)    s_Text = Replace(s_Text, vbCrLf, "")    s_Text = Replace(s_Text, vbCr, vbLf)    s_Text = Replace(s_Text, Chr(7), "")    s_Text = Replace(s_Text, vbCrLf, "")    s_Text = Replace(s_Text, vbCrLf, vbLf)    s_Text = Replace(s_Text, vbVerticalTab, vbLf)    s_Text = Replace(s_Text, vbTab, "")              End Function

3.     ExecuteStatement / ExecuteGlobal Statement

Execute one or more specified statements,defined as strings.

ExecuteGlobal: it executes the statement inglobal scope:

Dim x :x = 4 Call Func1 Sub Func1()                Dim x : x = 3                Execute "print x"                                                            'x= 3 local                ExecuteGlobal "print x"                                             'x=4 global End Sub

4.     Arrays: fixed length & dynamic

a.     Fixed length arrays:

Dix x(2)                   ‘ 2 dimensional

b.     Dynamic Arrays:

Dim x()

ReDim x(3)

用關鍵字Preserve 來保留數組原來的值。

ReDim x(2,3) ReDim Preserve x(2,5)          ‘保留了原來x(2,3)的值

               Note:4.1 you can reDim as often as we want. But it can destroy the previous values.

4.2  多元數組用關鍵字Preserve， 隻能 ReDim 數組的最後一維。

ReDim Preserve x(3,5)                      ‘error popup

5.     Optional arguments in VBS

QTP does not support optional parameters butcan be achieved by following ways:

Method 1: Optional arguments using Null/Empty values 'Function checks if param is null or empty Function IsMissing(ByVal param)    On Error Resume Next    IsMissing = IsNull(param) Or IsEmpty(param)    If err.Number<>0  Then                   IsMissing = False    End If End Function 'this function can have value including Null or Empty Function Method_1(ByVal param1, ByVal param2)                If IsMissing(param1) Then param1="default1"                If IsMissing(param2) Then param1="default2"                               End Function

Method 2: Optional arguments using Array members Function Method_2(Arguments)    Dim ArrayArg                'check Arguments if missing                'check Arguments if array                If VarType(Arguments) < vbArray Then Arguments = Array(Arguments)                               'check if the dimension is missing                               ArrayArg = Arguments                ReDim Preserve ArrayArg(2) '2 dimension is expcted                               'then to see each dimension of Array is missing or not End Function

Method 3: Optional arguments using an Array of (Key, value)pairs 思路： 把參數和值放到字典中。 Set Params = CreateObject("Scripting.Dictionary")

Method 4: Optional arguments using an Array of (key:=value) pairs

Method 5: Optional arguments using an Array of Hybrid (Key, value of Key:=value) paris