Characters and Strings

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• Characters and Strings

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Characters

• New primitive char
• char letter
• letter a
• char letter2 C
• Because computers can only represent numbers,
  Characters have ASCII values

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Characters
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Characters

• These values can be used in comparisons and in
  calculations
• char letter a c
• char letter (char) 70
• int valueOfX (int) X
• a lt b

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Strings

• Strings are special objects
• A String is a sequence of characters treated as a
  single value
• String s new String(xyz)
• Its special because you can create them many
  different ways
• String s xyz
• String s inputBox.getString( )
• s ABC

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Strings

• Strings are special objects
• A String is a sequence of characters treated as a
  single value
• String s new String(xyz)
• Its special because you can create them many
  different ways
• String s new String(xyz)
• String s new String(inputBox.getString( ) )
• s new String( s ABC)

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Strings

• Common String methods
• length( ) - returns the length of the String
• charAt(int i) returns char at position I
• CompareTo(String s) 0 if equal, negative if
  this String is lt s, positive if this String gt s
• Substring(int beginIndex, int endIndex) returns
  a new String
• equals(String s) true or false
• equalsIgnoreCase(String s) true or false
• Know these!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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Strings

• Example
• // count the number of letter as in a string
• int count 0
• char a a
• String s inputBox.getString()
• for (int i 0 I lt s.length( ) i)
• if (s.charAt( i ) a)
• count