Regular Expressions use in QTP/UFT

How to use Regular Expressions in QTP\UFT

  Regular Expression can be used to find the text strings and objects with varying values.

·         Regular Expression will be helpful when the expected value of any object or string is regularly changing but in fixed pattern.

·         These are strings which defines the search phrases on the basis of special character provided in the expression.

·         Scenarios where Regular Expression can be utilized:

      1.      Defining the property values of an object

      2.      Defining the expected values for checkpoints

      3.      Defining pop-up window conditions in recover scenario 

 Points about Regular Expression:

v  It can be created only for strings only.

v  Period (.), hyphen (-), asterisk (*), caret (^), brackets ([ ]), parentheses (()), dollar sign ($), vertical line (|), plus sign (+), question mark (?), and backslash (\) are special characters used to create RE.

v  Any of the above mentioned special characters is preceded by a backslash (\), QTP treats it as a literal character.

         Various Regular Expression Pattern used in QTP: 

Alpha Numeric Character:

1.      Matching Any Alpha Numeric Character Including the Underscore ( \w )

2.      Matching Any Non-Alpha Numeric Character (\W) will match any special character other than underscore. Please note case of W in this case.

Digit Character: 

1.      Matches a digit character (\d) matches a digit value.

2.      Matching a non-digit character (\D) matches a non digit value

    Single Character:

1.      Matching Any Single Character (.) e.g. def. Will match ‘def’ followed by any            character.

2.      Matching Any Single Character in a List ( [xy] ) e.g. [de] will match either d or e

3.      Matching Any Single Character Not in a List ( [^xy] ) e.g. 4[^56] will match all values between 41 to 49 except 45 and 46.

4.      Matching Any Single Character within a Range ( [x-y] ) e.g. : 2[1-3] will match 21,22, and 23.

Specific Characters:

1.      Matching Zero or More Specific Characters ( * ) This matches zero or more occurrences of the preceding character. e.g de* will match dee, deeee, d and so on. Similarly d.* will match d, ds, deee, and so on, since preceding character here is “.”.

2.      Matching One or More Specific Characters ( + ) Only difference from * is it will match for minimum one character. e.g se+t will match seat,set but not st as in above case.

3.      Matching Zero or One Specific Character ( ? ) A question mark (?) instructs QTP to match zero or one occurrences of the preceding character. For example: ze?s matches zes and zs, but nothing else

4.      Matching One of Several Regular Expressions ( | )  e.g date|day will match either of date or day. If we write da(t|e)ay, it will match datay or daeay.

Line:

1.      Matching the Beginning of a Line ( ^ ) This will match only if match is found at beginning of line.

2.      Matching the End of a Line ( $ )  This will match only if match is found at end of line.

Boundary:

1.      Matching a word at boundary(\b) e.g end\b will match testend but not in gendit.

Regular Expression Examples:

 There are 3 properties and 3 methods in the Regular Expression.

Properties:

1.      Pattern

2.      Global

3.      Ignorecase

Methods:

                                                                                        

1.      Execute( )

2.      Test()

3.      Replace()

Properties syntax:

1) Pattern:-  Property is used to store expected expression for matching.

    Syntax:-                                                                      

    set r=new regexp

    r.pattern=”\w”

    r.global=true/false

2) Global:- Property is used to specify pattern matching on given text until end of text.

    Syntax:-         

     set r=new regexp

     r.pattern=”\d”

     r.global=true/false

3) Ignorecase:- Property is used to specify case sensitiveness

.   Syntax:-      

     set r=new regexp

     r.pattern=”[A-Z][a-z]+”

      r.global=true

      r.ignorecase=true

Methods Examples:

1)  Execute( ):- Method is used to apply given pattern on given text and find matched values in text.

     Ex:-                  

     set rg=new regexp

     rg.pattern=”[0-5]+”

     rg.global=true

     st=”mno123def 34 zsdfg45gh”

     set x=rg.execute(st)

     for each y in x

          print(y.value)

     next

2) Test:-Method is used to apply given pattern on given text for matching. If pattern was matched with 

text, then this method returns true.

     Ex:-  

     set r=new regexp

     r.pattern=”[0-6]+”

     r.global=true

     x=”633544”

     if r.test(x) then

       print(“Data is matched”)

    else

      print(“Mismatch in data”)

    end if

3)  Replace( ):- Method is used to replace matched text with other text.

     Ex:-    

     set r=new regexp

     r.pattern=”[0-5]+”

     r.global=true

     x=”This is QTP machine 5”

     r.replace(x,”I”)

     print(x)