STRING WITH STRING CONSTRUCTORS

String:

The class String and String Buffer are part of the java.lang package.

String is a sequence of characters. But unlike many other languages that implement string as characters arrays, java implement string as object of type string.

Implementing string as built in objects allows java to provide a full complement of features that make string handling convenient. Also string objects can be constructed a number of ways, making it easy to obtain when needed.

The string handling  in the java is done with the help of the two classes present in the package java.lang

                        i.  String

                        ii. StringBuffer

1. String: String is a sequence of character and to store them we will use the object of the String class.

The constructors of the String class are:

(a) String()

            It is the default constructor of the String class and it will create a String class object initialized with a blank string. The general form is.

                        String objectname=new String();

E.g.

                        String s=new String();

                        System.out.println(s);

Output:

                        (No output)

(b) String(char [ ] ) :

This constructor is used to initialise the String class object with the elements of the character array.

The general form is.

                        String s=new String(ch);

Where, ch is the character array.

E.g.

                        char ch[ ]={'B','M','B','P',’N’,’T’};

                        String s=new String(ch);

                        System.out.println(s);

                        output:

BMBPNT

(c) String(char [ ],int ,int )

            This constructor is used to create a String class object and initialise it with the specific group of characters from the character array.         The general form is.

                        String(ch,index,Mchars)

Where:

            ch is the character array used for the initiation of the String.

index specify the starting index position from where we want to start extracting the characters from the character array.

            Mchars specify the number of characters to be extracted from the starting index position.

E.g.

                        char ch[ ]={'C','o','m','p','u','t','e','r'};

                        String s=new String(ch,1,3);

                        System.out.println(s);

                        Output :

                        omp

(d) String(byte [ ])

            This constructor will create a String class object and initialise it with the character corresponding to the numeric values stored in the byte array. These numeric values are taken as ASCII values.   The general form is.

                                    String objectname=new String(b);

Where,

                        b is the byte aray.

E.g.

                        byte b[ ]={65,66,67,68,69,70};

                        String s=new String(b);

                        System.out.println(s);

                        output :

                        ABCDEF

(e)String(byte [ ],int,int)

            This constructor is used to initialise the String class object with the specific group of the characters corresponding to the numbers stored in the byte array. The general form is.

                        String objectname=new String(b,index,nchars);

E.g.

                        byte b[ ]={65,66,67,68,69,70,71};

                        String s=new String(b,1,4);

                        System.out.println(s);

                        output:

                        BCDE

(f) String(String)

            This constructor is used to create a string class object and initialise it with another String class object. The general form is.

                        String objectname=new String(String obj);

E.g.

                        String s=new String("computer");

                        System.out.println(s);

Output :          

                        computer