Static Data Member

1
Static Data Member

• Static variables are sometimes called class
  variables
• Normally, each object has its own data space
• If a variable is declared as static, only one
  copy of the variable exists
• private static float price
• Memory space for a static variable is created as
  soon as the class in which it is declared is
  loaded

2
Static Data Member

• All objects created from the class share access
  to the static variable
• Changing the value of a static variable in one
  object changes it for all others
• Static methods and variables often work together

3
Student

• public class Student
• private static int staticNumber 0
• private int studentNumber
• private String name,address
• Student(String name,String address)
• this.name name
• this.address address
• studentNumber staticNumber
• staticNumber
• public void print()
• System.out.println("Name " name)
• System.out.println("Address " address)
• System.out.println("Number " studentNumber
  )

4
TestStudent

• public class TestStudent
• public static void main(String args)
• Student s1 new Student("Moshe","Beer-Sheva")
  
• s1.print()
• Student s2 new Student("Shay","Eilat")
• s2.print()
• System.out.println(s1.HowMany())
• System.out.println(s2.HowMany())
• System.out.println(Student.HowMany())

5
StringTokenizer

• The StringTokenizer class makes it easy to break
  up a string into pieces called tokens.
• By default the delimiters for the tokens are the
  white space characters (space, tab, new line)
• The StringTokenizer class is defined in the
  java.util package

6
StringTokenizer

• StringTokenizer st new StringTokenizer("this is
  a test")
• hasMoreTokens() Tests if there are more tokens
  available from this tokenizer's string.
• nextToken() Returns the next token from this
  string tokenizer.

7
StringTokenizer

• import java.util.
• public class Poem
• public static void main(String args)
• String poem
• "Que sera sera, whatever will be will be"
• StringTokenizer tokenizer
• new StringTokenizer(poem)
• String token
• while (tokenizer.hasMoreTokens())
• token tokenizer.nextToken()
• System.out.println(token)