1. Microsoft Visual Basic 2005: Reloaded Second Edition
Chapter 6
String Manipulation and More Controls

2. Objectives After studying this chapter, you should be able to:
Determine the number of characters contained in a string
Remove characters from a string
Replace one or more characters in a string
Insert characters within a string
Search a string for one or more characters
Microsoft Visual Basic 2005: Reloaded, Second Edition

3. Objectives (continued)
Access characters contained in a string
Compare strings
Include radio buttons in an interface
Include check boxes in an interface
Microsoft Visual Basic 2005: Reloaded, Second Edition

4. Manipulating Strings in Visual Basic
Most applications need to manipulate string data in some fashion
String properties and methods are used to manipulate string data
Microsoft Visual Basic 2005: Reloaded, Second Edition

5. Determining the Number of Characters Contained in a String
Microsoft Visual Basic 2005: Reloaded, Second Edition

6. Determining the Number of Characters Contained in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

7. Determining the Number of Characters Contained in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

8. Determining the Number of Characters Contained in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

9. Removing Characters from a String
TrimStart method: removes one or more characters from the beginning of a string
TrimEnd method: removes one or more characters from the end of a string
Trim method: removes one or more characters from both the beginning and end of a string
Each of these methods returns a string with the appropriate characters removed
Microsoft Visual Basic 2005: Reloaded, Second Edition

10. Removing Characters from a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

11. Removing Characters from a String (continued)
trimChars argument:
Comma-separated list of characters to be removed
If omitted, spaces will be removed
Default value is the space character: “ ”
Microsoft Visual Basic 2005: Reloaded, Second Edition

12. Removing Characters from a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

13. Removing Characters from a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

14. The Remove Method Remove method: Index:
Removes characters from a string
Can remove one or more characters located anywhere in the string
Returns a string with the appropriate characters removed
Index:
The position of a character in a string
Is zero-relative (starts with 0 as first position)
Microsoft Visual Basic 2005: Reloaded, Second Edition

15. The Remove Method (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

16. The Remove Method (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

17. The Remove Method (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

18. The Remove Method (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

19. Replacing Characters in a String
Replace method: replaces a sequence of characters in a string with another sequence of characters
Microsoft Visual Basic 2005: Reloaded, Second Edition

20. Replacing Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

21. Replacing Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

22. Replacing Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

23. Replacing Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

24. The Mid Statement Mid statement:
Replaces a specified number of characters in a string with characters from another string
targetString argument: the string in which characters are to be replaced
replacementString argument: the replacement characters
start argument: the starting position for the replacement
count argument: number of characters to replace
Microsoft Visual Basic 2005: Reloaded, Second Edition

25. The Mid Statement (continued)
Character position of characters in the string starts with 1 (not the same as index)
Count argument is optional
Microsoft Visual Basic 2005: Reloaded, Second Edition

26. The Mid Statement (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

27. The Mid Statement (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

28. The Mid Statement (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

29. Inserting Characters in a String
PadLeft method: inserts characters at the beginning of a string
PadRight method: inserts characters at the end of a string
length argument: represents the total length of the desired resulting string
character argument:
The character used to pad the string
Default value is the space character
Microsoft Visual Basic 2005: Reloaded, Second Edition

30. Inserting Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

31. Inserting Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

32. Inserting Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

33. Inserting Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition

34. Inserting Characters in a String (continued)
Microsoft Visual Basic 2005: Reloaded, Second Edition