2.regular expressions

Regular Expressions



What is Regular Expressions ?



Common Scenarios where Regular Expressions are used



Regular Expression submatch String



Using Regular Expressions for Property Values



Using Regular Expressions in Checkpoints



Case Study



Session Wrap-Up
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Regular Expressions



A regular expression is a string that describes or matches a set of strings,
according to certain syntax rules.
or
A regular expression, often called a pattern, is an expression that describes a set
of strings. They are usually used to give a concise description of a set, without
having to list all elements.



Regular expressions are used by many text editors and utilities to search and
manipulate bodies of text based on certain patterns.



Many programming languages support regular expressions for string
manipulation.
For example, Perl has a powerful regular expression engine built directly into its
syntax.



The set of utilities (including the editor sed and the filter grep) provided by Unix
distributions were the first to popularize the concept of regular expressions.



The origin of regular expressions lies in Automata Theory and formal language
theory (both part of Theoretical Computer Science.



Can use regular expressions for :
- Defining the property values of an object in dialog boxes.
- Parameterizing a step.
- Creating checkpoints with varying values.

Regular Expressions

1.

Using the Backslash Character



A backslash () instructs QuickTest to treat the next character as a literal
character, if it is otherwise a special character .



The backslash () can also instruct QuickTest to recognize certain ordinary
characters as special characters. Example: QuickTest recognizes n as the special
newline character.



Example:





matches the literal character
( matches the literal character (

Scenario: If you are looking for a Web site called:
mercurytours.mercuryinteractive.com the period would be mistaken as an
indication of a regular expression.
• To indicate that the period is not part of a regular expression, you would enter it
as follows:
mercurytours.mercuryinteractive.com


Regular Expressions

2. Matching Any Single Character

 A period (.) instructs QuickTest to search for any single

character (except for n).
For example:
Welcome.

matches Welcomes, Welcomed, or Welcome followed by a
space or any other single character.
 A series of periods indicates the same number of unspecified

characters.

 To match any single character including n, enter:

(.|n)


Regular Expressions

3. Matching Any Single Character in a List
•

Square brackets instruct QuickTest to search for any single character within a list of characters.

•

Example, to search for the date 2000, 2001, or 2002, enter:
200[012]

4. Matching Any Single Character Not in a List Iterative
constructs.
•

When a caret (^) is the first character inside square brackets, it instructs QuickTest to match any
character in the list except for the ones specified in the string.

•

Example:

[^ab]

matches any character except a or b.
Note: The caret has this special meaning only when it is displayed first within the brackets.


Regular Expressions

5. Matching Any Single Character within a Range.
•

In order to match a single character within a range, you can use square brackets ([ ])
with the hyphen (-) character.

•

Example : To match any year in the 2000s, enter:
200[0-9]

6. Matching Zero or More Specific Characters Functions and subroutines.
•
•

An asterisk (*) instructs QuickTest to match zero or more occurrences of the
preceding character.
For example:
ca*r

matches car, caaaaaar, and cr.


Regular Expressions

7. Matching One or More Specific Characters.
•

A plus sign (+) instructs QuickTest to match one or more occurrences of the

•

Example:
ca+r

matches car and caaaaaar, but not cr.

8. Matching Zero or One Specific Character.
•

A question mark (?) instructs QuickTest to match zero or one occurrences of the

•

Example:
ca?r

matches car and cr, but nothing else.


Regular Expressions

9. Grouping Regular Expressions.
•

Parentheses (()) instruct QuickTest to treat the contained sequence as a unit, just as
in mathematics and programming languages.

•

Using groups is especially useful for delimiting the argument(s) to an alternation
operator ( | ) or a repetition operator ( * , + , ? , { } ).

10. Matching One of Several Regular Expressions.
•

A vertical line (|) instructs QuickTest to match one of a choice of expressions.

•

For example:
Too|bar causes QuickTest to match either Too or bar.
To(o|b)ar causes QuickTest to match either Tooar or Tobar.


Regular Expressions

11. Matching the Beginning of a Line.
•

A caret (^) instructs QuickTest to match the expression only at the start of a line, or
after a newline character.

•

Example:
Phone matches Phone within the lines—Phone, my Phone, and Phone list, while
^ Phone matches Phone only in the lines—Phone and Phone Numbers.

12. Matching the End of a Line.
•

A dollar sign ($) instructs QuickTest to match the expression only at the end of a line,
or before a newline character.

•

Example:
Phone$ matches Phone only in the line—my Phone.


Regular Expressions

13. Matching Any Alphanumeric Character Including the Underscore
•

w instructs QuickTest to match any alphanumeric character and the underscore (AZ, a-z, 0-9, _).

•

Example:
w* causes QuickTest to match zero or more occurrences of the alphanumeric
characters—A-Z, a-z, 0-9, and the underscore (_). It matches xyz, p8aj, or
1_uLeu_4.
w{3} causes QuickTest to match 3 occurrences of the alphanumeric characters A-Z,
a-z, 0-9, and the underscore (_). It matches xy4, c7_, or p_n.


Regular Expressions

14. Matching Any Non-AlphaNumeric Character
•

W instructs QuickTest to match any character other than alphanumeric characters
and underscores.

•

Example:
W matches &, *, ^, %, $, and #.

15. Combining Regular Expression Operators
•

You can combine regular expression operators in a single expression to achieve the
exact search criteria you need.

•

Example,
start.*

matches start, started, starting, starter, etc.


Regular Expressions



A SubMatches collection contains individual submatch strings .



Strings following the specified pattern will get stored in submatches collection when
regular expression is executed.



Case Study: Verify the PATTERNS of email-ids.

Problem: Fetch submatch email-ids strings which follows
the following the regular
expression
pattern "w{6}.w{6}@w{9}.w{3}“.


Solution:











Create a regular expression using New.
Set the pattern using pattern property.
Execute search using Execute Method.
FirstIndex property- It uses a zerobased offset from the beginning of the
search string .
Value property will give exact value at
particular location.
For Each...Next Statement
Used to Repeats a group of statements
for each element in an array or
collection.
Patterns Property- It Sets or returns the
regular expression pattern being
searched for


Regular Expressions



Used to change value of a property in a predictable way during each run session.



By default, the value of all Property objects added to a Properties collection are treated as
regular expressions.



Use the RegularExpression property to change this setting for a specific Property object in the
collection.



Syntax
PropertiesColl(Property).RegularExpression = BooleanSetting
Argument
Property

Variant

The property for which you want to specify the regular
expression value. Specify the name of the property or its
position in the collection.

BooleanSetting



Type

Description

Boolean

The new value for the specified property.

Example
The following example uses the RegularExpression property to set the value of the PropName Property
object as a literal value.
set MyDesc = Description.Create()
MyDesc("PropName").Value = PropValue
MyDesc("PropName").RegularExpression = FALSE

Regular Expressions



We can set a new value for an existing Property object in the properties collection, or adds a new property
object if the specified property name does not exist in the Properties collection.



For Example : If we want to change the name of userName WebEdit control to LoginName then following
code should be added.


Regular Expressions



Case Study
•

Problem: Consider a site includes a form in which the user inputs data
and clicks the Send button to submit the form.

•

When a required field is not completed, the form is displayed again
for the user to complete.

•

When resubmitting the form, the user clicks the Resend button.

•

Solution: Define the value of the button's name property as a regular
expression, so that QuickTest ignores variations in the button name
when clicking the button.


Regular Expressions



Set the expected value of an object's property as a regular expression so
that an object with a varying value can be verified.



When creating a text checkpoint to check that a varying text string is
displayed on your Web site or application, you can define the text string
as a regular expression.



Case
Study
Problem : Check that every window and dialog box in the application
contains the name of the application followed by a hyphen (-) and a
descriptive title.
Solution : Add a checkpoint to each dialog box object in the test to check
that the first part of the title contains the name of the application followed
by a hyphen. .

Regular Expressions

•

Problem:

•

Create a text checkpoint on a date text string that changes according to the selected flight
date.

•

Solution:
Define the date as a regular expression so that the checkpoint checks that the captured
text string matches the expected format, rather than checking the exact text.
In the Active Screen, scroll up and highlight the date. Right-click the highlighted string and
select Insert Text Checkpoint. The Text Checkpoint Properties dialog box opens.
Replace the current date with [0-1][0-9]/[0-3][0-9]/200[0-9].
This instructs QuickTest to check that each character in the selected text matches the
number-range format defined by the regular expression.


Regular Expressions



Running and Analyzing a Test with Regular
Expressions



Examine the checkpoint results.



The checkpoint passed because the text was displayed in the format
specified by the regular expression

•

Problem: Consider a site includes a form in which the user inputs data
and clicks the Send button to submit the form.
 When a required field is not completed, the form is displayed again for the

user to complete.
 When resubmitting the form, the user clicks the Resend button.
•

Solution: Define the value of the button's name property as a regular
expression, so that QuickTest ignores variations in the button name
when clicking the button.


Regular Expressions

Q & A….


Regular Expressions



Regular expressions enable QuickTest to identify
objects and text strings with varying values.



We can use regular expressions when:
 Defining the property values of an object in dialog boxes or in
programmatic descriptions
 Parameterizing a step
 Creating checkpoints with varying values



Use the RegularExpression property to change this
setting for a specific Property object in the collection.


2.regular expressions

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