Microsoft Visual Basic 2005: Reloaded Second Edition

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Microsoft Visual Basic 2005 Reloaded Second
Edition

• Chapter 6
• String Manipulation and More Controls

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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

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Objectives (continued)

• Access characters contained in a string
• Compare strings
• Include radio buttons in an interface
• Include check boxes in an interface

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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

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Determining the Number of Characters Contained in
a String
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Determining the Number of Characters Contained in
a String (continued)
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Determining the Number of Characters Contained in
a String (continued)
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Determining the Number of Characters Contained in
a String (continued)
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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

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Removing Characters from a String (continued)
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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

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Removing Characters from a String (continued)
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Removing Characters from a String (continued)
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The Remove Method

• Remove method
• 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)

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The Remove Method (continued)
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The Remove Method (continued)
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The Remove Method (continued)
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The Remove Method (continued)
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Replacing Characters in a String

• Replace method replaces a sequence of characters
  in a string with another sequence of characters

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Replacing Characters in a String (continued)
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Replacing Characters in a String (continued)
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Replacing Characters in a String (continued)
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Replacing Characters in a String (continued)
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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

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The Mid Statement (continued)

• Character position of characters in the string
  starts with 1 (not the same as index)
• Count argument is optional

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The Mid Statement (continued)
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The Mid Statement (continued)
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The Mid Statement (continued)
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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

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Inserting Characters in a String (continued)
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Inserting Characters in a String (continued)
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Inserting Characters in a String (continued)
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Inserting Characters in a String (continued)
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Inserting Characters in a String (continued)