String class supports different types of constructors. Lets see the different types of constructors with example.
Default constructor
|
1 |
String str= new String(); |
The above will create an instance of string without any characters.
String object with character array as parameters
If you want to create String with initial values , We have variety of constructors
String (char chars[]))
We can also specify sub range of character array for initializing string .
String (char chars[],int startIndex,int numberOfCharacters)
Example:
|
1 2 3 4 5 6 7 8 9 10 |
package com.j2eereference.coreJava; public class StringConstructors { public static void main(String[] args) { char chars[] = { 'a', 'b', 'c', 'd', 'e', 'f' }; String str1 = new String(chars); String str2 = new String(chars, 2, 3); System.out.println(str1); System.out.println(str2); } } |
output
abcdef
cde
String object from another string object
We can create string object from another String object as below.
|
1 2 3 4 5 6 7 8 9 |
package com.j2eereference.coreJava; public class StringConstructors { public static void main(String[] args) { String str1 = new String("j2eereference"); String str2 = new String(str1); System.out.println(str1); System.out.println(str2); } } |
Output
j2eereference
j2eereference
String constructor with byte array
We can create String object from byte array as below.
String(byte asciiChars[])
and
String(byte asciiChars[],int startIndex,int numberOfCharacters)
|
1 2 3 4 5 6 7 8 9 10 |
package com.j2eereference.coreJava; public class StringConstructors { public static void main(String[] args) { byte ascii[] = { 65, 66, 67, 68, 69, 70 }; String str1 = new String(ascii); String str2 = new String(ascii, 2, 3); System.out.println(str1); System.out.println(str2); } } |
output
ABCDEF
CDE
String constructor with Unicode
Java 1.5 supports Unicode character set as argument in string constructor.
String(int codePoints[],int startIndex,int numberOfCharacters)
Here codePoints is the array contains Unicode points
String constructor with StringBuilder
Java 1.5 supports string constructors with StringBuilder parameter.
String(StringBuilder strBuilder)
|
1 2 3 4 5 6 7 8 |
package com.j2eereference.coreJava; public class StringConstructors { public static void main(String[] args) { StringBuilder strBuilder = new StringBuilder("j2eereference"); String str = new String(strBuilder); System.out.println(str); } } |
output
j2eereference
Hemant says
Really, I impressed by this site. I saw many java sites but this is one of the best site.
This is simple and full of knowledge.
ravi krishnarpan says
This site is simply the best !Thanks for imparting this kind of knowledge in simple but sublime
language .