String - I

String in java is a special class of objects which represents characters. Java String is a immutable object and immutable object cannot be modify. Therefore, when a String method used that always returns a new String instead of modifying the existing. String in java has its all attributes marked as final. If we go for concatenation, another string object will be created and the value is going to assign for that object, so we are going to have two objects.

Because String and its attributes are declared as final, the system can pass the sensitive read-only information without disturbing about alteration.

String Functions Some of the most utilized function of String class are  as follows:

String.length() – to find the length of a string value.

Example:

String Str=“Hello Java”;

Int L=Str.length(); // Value of L = 10

String.charAt(int) – extract a character from the said string from given position.

Example:

String Str=“Hello Java”;

System.out.println(Str.charAt(1)); // Output -> 'e'

String1.equals(String2) – check equality between two string and return a Boolean value as result.

Example:

String Str=“Hello”;

System.out.println(Str.equals(“HELLO”));  // Output -> 'false'

String1.equalsIgnorecase(String2) - check equality between two strings while ignoring he case difference and return a Boolean value as result.

Example:

String Str=“Hello”;

System.out.println(Str.equalsIgnorecase(“HELLO”)); //Output -> 'true'

String1.compareTo(String2) – Compare between two string( relevant to the ASCII values of each character), if both equal it return 0, if String1 is smaller than String2 then it will return a negative value and if  String1 is bigger than String2 then it will return a positive value.

Example:

String Str=“Hello”;

System.out.println(Str.comapreTo(“HELLO”)); // "e - E" means 101 - 69 = -32

// it will return 32 as Ascii value of ‘e’ is 101 and the Ascii  value of 'E' is 69 is and difference is 32, therefore the value store in variable ‘Str’ is bigger than the other string.

compareToIgnoreCase(String str) 

int compareToIgnoreCase(String str) compares two strings while ignoring the case or rather compare two string lexicographically.

Example:

String Str="This is Test";
String Str1="THIS IS TEST";
int t=Str.compareToIgnoreCase(String Str1);//return 0.

String.substring(int) – Extract all the string from given position until end.

Example:

String Str=“I love my contry”;

System.out.println(Str.substring(7)); // Output :  my country

String.substring(int,int) - Extract all the string from starting position up to left of end position.

Example:

String Str=“I love my contry”;

System.out.println(Str.substring(0,6)); // Output :  I love