CS 596 Client-Server Programming
Classes of Basic Types

1. Classes for Basic Types
   1. Strings
   2. String vs. char[] vs. C/C++ char*
   3. Reading Command Line Arguments
   4. Numeric Classes

class StringExample 
{
	public static void main( String args[] ) 
	{
		String  firstName  = "    Roger    ";
		String  lastName  = "    Whitney     ";
		String  fullName  =  firstName  + lastName;
		System.out.println(  fullName  );

		firstName  =  firstName.toLowerCase();
		lastName  =  lastName.toUpperCase();
		System.out.println(  firstName  );

		firstName  =  firstName.trim();   // trim leading, trailing
		lastName  =  lastName.trim();   // white space

		lastName  =  lastName.replace( 'I', 'a' );
		System.out.println(  firstName  + lastName  );

		String floatAsString  =  String.valueOf( 13.4e+5f);
		System.out.println(  floatAsString  );
	}
}

    Roger        Whitney
    roger
rogerWHaTNEY
1.34e+06

Array of characters

Only array operations are supported

Is a class with numerous operations

Integrated into Java's ~200 classes

Strings are constant,

Their values cannot be changed after creation

class CommandLineExample 
{
	public static void main( String args[] ) 
	{
		System.out.println(  args.length  );

		for ( int k = 0; k < args.length;  k++ )  
		{
			System.out.println( "Argument " + k + "\t" + args[ k ] );
		};

		Float secondArgument = Float.valueOf( args[ 1 ] );
		System.out.println( secondArgument );
	}
}

"The numeric classes provide an object wrapper for numeric data values and serves as a place for numeric-oriented operations. A wrapper is useful because most of Java's utility classes require the use of objects. Since int, long, float and double are not objects in Java, they need to be wrapped in a class instance."

class NumericClassesExample 
{
	public static void main( String args[] ) 
	{
		Integer  height  =  new Integer( 10 );
		Integer  width  =  new Integer( 25 );
		Integer  depth  =  25;				// Compile error

		Integer area;
		area =  height * width;				// Compile error
		area =  new Integer(height.intValue() * width.intValue() );

		System.out.println(  area  );

		String  areaAsString  =  area.toString();

		int areaAsInt  =  area.intValue();
		long areaAsLong  =  area.longValue();

		System.out.println(  Integer.MAX_VALUE  );
	}
}