Java - String

String:

Strings, which are widely used in Java programming, are a sequence of characters. In the Java programming language, strings are objects.

The Java platform provides the String class to create and manipulate strings.

Creating Strings:

The most direct way to create a string is to write String greeting = "Hello world!";

Whenever it encounters a string literal in your code, the compiler creates a String object with its value in this case, "Hello world!'.

public class StringDemo{

public static void main(String args[]){ char[] helloArray = { 'h', 'e', 'l', 'l', 'o', '.'}; String helloString = new String(helloArray); System.out.println( helloString );

}

}

String Length: Methods used to obtain information about an object are known as accessor methods. One accessor method that you can use with strings is the length() method, which returns the number of characters contained in the string object .

public class StringDemo {

public static void main(String args[]) { String palindrome = "Dot saw I was Tod"; int len = palindrome.length();

System.out.println( "String Length is : " + len );

}

}

Concatenating Strings: The String class includes a method for concatenating two strings:

string1.concat(string2);

This returns a new string that is string1 with string2 added to it at the end. You can also use the concat () method with string literals.

Some String Methods:

char charAt (int index): Returns the character at the specified index. int compareTo(Object o): Compares this String to another Object .

int compareTo(String anotherString): Compares two strings lexicographically.

int compareToIgnoreCase(String str): Compares two strings lexicographically, ignoring case differences.

String concat (String str): Concatenates the specified string to the end of this string. boolean equals(Object anObject ): Compares this string to the specified object .

int indexOf (int ch): Returns the index within this string of the first occurrence of the specified character.

int length(): Returns the length of this string.

String replace(char oldChar, char newChar):Returns a new string resulting from replacing all occurrences of oldChar in this string with newChar.

String[] split (String regex): Splits this string around matches of the given regular expression.

String toLowerCase(): Converts all of the characters in this String to lower case using the rules of the default locale.