String Manipulation

1. ) Reading characters from String:

char charAt(index i)

Returns char at specified index. An index ranges from 0 to length() -1.

2. ) Searching characters in String

String class provides indexOf method which searches for the specified character inside the string object. This method has been overloaded. If the search is successful, then it returns the index of the char otherwise -1 is returned.

int indexOf(int c)

Returns the index of first occurrence of the argument char.

int indexOf(int c, int fromIndex)

Finds the index of the first occurrence of the argument character in a string, starting at the index specified in the second argument.

int indexOf(String str)

Finds the start index of the first occurrence of the substring argument in a String.

int indexOf(String str, int fromIndex)

Finds the start index of the first occurrence of the substring argument in a String, starting at the index specified in the second argument.

The String class also provides methods to search for a character or string in backward direction. These methods are given below.

int lastIndexOf(int ch)
int lastIndexOf(int ch, int fromIndex)
int lastIndexOf(String str)
int lastIndexOf(String str, int fromIndex)