Monday, 12 December 2011

string manipulation in java example - Creating Strings


The most direct way to create a string is to write:
String greeting = "Hello world!";
In this case, "Hello world!" is a string literal—a series of characters in your code that is enclosed in double quotes. Whenever it encounters a string literal in your code, the compiler creates a String object with its value—in this case, Hello world!.
As with any other object, you can create String objects by using the new keyword and a constructor. The String class has thirteen constructors that allow you to provide the initial value of the string using different sources, such as an array of characters:
char[] helloArray = { 
'h', 'e', 'l', 'l', 'o', '.'
};
String helloString = new String(helloArray);
System.out.println(helloString);
The last line of this code snippet displays hello.

Note: The String class is immutable, so that once it is created a String object cannot be changed. The String class has a number of methods, some of which will be discussed below, that appear to modify strings. Since strings are immutable, what these methods really do is create and return a new string that contains the result of the operation.