The String Constructors

The String class supports several constructors. To create an empty String, call the default constructor. for example,
String s=new String();
will create an instance of String with no characters in it.
The String class provides a variety of constructor to handle this. To create a String initialized by an array of characters, use the constructor show here:
String(char arr[]) // array name is arr.
Here is an example:
char arr[]={'m','a','n','o','j'}; String s=new String(arr);
This constructor initializes s with the string "manoj".
You can secify a subrange of a character array as an initializer using the following constructor:
String(char arr[], int startIndex, int numChars)
Here, startIndex specifies the index at which the subrange begins, namd numChars specifies the number of characters to use. Here is an example:
char arr[]={'m','a','n','o','j'}; String s=new String(arr, 2, 3)
This initializes s which the characters "noj".
You can construct a String object that contains the same character sequence as another String object using this constructor:
String(String strObj)
Here, strObj is String object. consider this example:
class makeString{ public static void main(String args[]){ char c[]={'m','a','n','o','j'}; String s1=new String(c); String s2=new String(s1); System.out.println(s1); System.out.println(s2); }}
This programming generates the following output:
As you can see, s1 and s2 contain the same String.
Java's char type uses 16 bit to represent the basic Unicode character set, the typical formate for strings on the Internet uses arrays of 8-bit bytes constructed from the ASCII characters that initialize a string when given a byte array. Two forms are show here:
String(byte arr[]) String(byte arr[], int startIndex, int numChars)
Here is an example:
class subStringCons{ public static void main(String args[]){ byte b[]={77,65,78,79,74}; String s1=new String(b); System.out.println(s1); String s2=new String(b, 2, 3); System.out.println(s2); }}
This programming generates the following output:

You can construct a string from a StringBuffer by using the constructor shown here:
String(StringBuffer strBufObj)
You can construct a string from a StringBuilder by using the constructor shown here:
String(StringBuilder strBuildfObj)
The following constructor supports the extended Unicode character set:
String(int codePoints[], int startIndex, int numChars)
Here, codePrints is an array that contains Unicode code points.