Constructing a String
If you are constructing a string with several appends, it may be more efficient to construct it using a StringBuffer and then convert it to an immutable String object.
StringBuffer buf = new StringBuffer("Initial Text");
// Modify
int index = 1;
buf.insert(index, "abc");
buf.append("def");
// Convert to string
String s = buf.toString();
Getting a Substring from a String
int start = 1;
int end = 4;
String substr = "aString".substring(start, end); // Str

If you have the better answer, then send it to us. We will display your answer after the approval.
Rules to Post Answers in CoolInterview.com:-

There should not be any Spelling Mistakes.

There should not be any Gramatical Errors.

Answers must not contain any bad words.

Answers should not be the repeat of same answer, already approved.

Answer should be complete in itself.

Name :*
Email Id :*
Answer :*
Verification Code	Not readable? Load New Code
Enter the above shown code:*
	Inform me about updated answers to this question