java.lang.Object Wrappers

• Primitive types such as int, char, float, etc. are NOT classes. Thus one cannot use methods such as

  • int var;
  • var.toString();

• ALL primitive types have associated wrappers:

  • Character myChar = new Character( 'A' );

• The Character class has methods such as:

  • if ( myChar.equals( ch ) ) ...
  • System.out.print( myChar.toString() );

• There are also many static (class) methods:

  • ch = Character.toLowerCase( myChar );
  • if ( Character.isUpperCase( myChar ) ) ...

• The methods in a wrapper class are also useful to convert types, such as a String to a Double.

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