STRING AND STRINGBUFFER CLASSES

String Handling:-

String Class:-

 Ø Set of characters or group of characters is known as String.
 Ø String is the class present in java.lang package.
 Ø String class consists of different set of methods.

PROGRAM:-

class Stringdemo
{
  public static void main(String args[])
  {
     char c[]={'j','a','v','a'};
     String s1=new String(c);
     String s2=new String(s1);
     System.out.println("From Object s1:"+s1);
     System.out.println("From Object s2:"+s2);
   }
}

File Name: -    Stringdemo.java    

Commands:-
                    javac     Stringdemo.java
java      Stringdemo

OUTPUT:-    
                     From Object s1: java
                     From Object s2: java


PROGRAM:-

class Stringdemo1
{
  public static void main(String args[])
  {
     String str="strings Class Demo";
     String s1=new String(str);
     System.out.println(s1.length());
     System.out.println(s1.charAt(5));
     System.out.println(s1.indexOf('s'));
     System.out.println(s1.lastIndexOf('s'));
     System.out.println(s1.substring(8));
     System.out.println(s1.substring(8,13));
     System.out.println(s1.toUpperCase());
     System.out.println(s1.toLowerCase());
    }
}

File Name: -    Stringdemo1.java    

Commands:-
                    javac    Stringdemo1.java
java     Stringdemo1

OUTPUT:-    
                       18
                        g
                         12
                         Class Demo
                         Class
                         STRINGS CLASS DEMO
                         Strings class demo

PROGRAM:-

class Stringdemo2
{
  public static void main(String args[])
  {
     String str="welcome to java";
     String s1=new String(str);
     System.out.println(s1.concat(" world"));
     System.out.println(s1.replace("j","J"));
     System.out.println(s1.startsWith("w"));
     System.out.println(s1.endsWith("a"));
   }
}

File Name: -    Stringdemo2.java    

Commands:-
                    javac    Stringdemo2.java
java     Stringdemo2

OUTPUT:-    
                     welcome to java world
                     welcome to Java
                         true
                         true

PROGRAM:-

class Stringdemo3
{
  public static void main(String args[])
  {
     String str="hello";
     String str1="hello";
     String str2="HELLO";
     if(str.equals(str1))
        System.out.println("Both are equal");
     else
         System.out.println("Both are not equal");
    if(str.equalsIgnoreCase(str3))
       System.out.println("Both are same");
   }
}

File Name: -    Stringdemo3.java    

Commands:-
                    javac    Stringdemo3.java
java     Stringdemo3

OUTPUT:-    
                        Both are equal
                        Both are same

StringBuffer:-

 Ø StringBuffer is the class present in java.lang package.  
 Ø StringBuffer class consists of different set of methods.
 Ø Here buffer allocates 2 bytes or 16bits of memory for every string.

PROGRAM:-

class SBdemo
{
  public static void main(String args[])
  {
     String str="welcome to java";
     StringBuffer sb=new StringBuffer(str);
     System.out.println(sb.length());
     System.out.println(sb.capacity());
     System.out.println(sb.charAt(5));
   }
}

File Name: -    SBdemo.java    

Commands:-
                    javac    SBdemo.java
java     SBdemo

OUTPUT:-    
                         15
                         31
                        m

PROGRAM:-

class SBdemo1
{
  public static void main(String args[])
  {
    String str="version of java";
    StringBuffer sb=new StringBuffer(str);
    System.out.println(sb.append(" is"));
    System.out.println(sb.append( 1.5));
    System.out.println(sb.replace(11,15,"JAVA"));
    System.out.println(sb.delete(16,18));
    System.out.println(sb.insert(16,"is"));
   }
}

File Name: -    SBdemo1.java    

Commands:-
                    javac    SBdemo1.java
java     SBdemo1

OUTPUT:-    
                        version of java is
                        version of java is 1.5
                        version of JAVA is 1.5
                        version of JAVA  1.5
                        version of JAVA is 1.5


PROGRAM:-

class SBdemo2
{
  public static void main(String args[])
  {
     String str="Java language";
     System.out.println("Before reversing:"+str);
     StringBuffer sb=new StringBuffer(str);
     System.out.println("After reversing:"+sb.reverse());
   }
}

File Name: -    SBdemo2.java    

Commands:-
                    javac    SBdemo2.java
java     SBdemo2

OUTPUT:-    
Before reversing:Java language
After reversing: egaugnal avaJ