Difference between two String statement

[deepak carter]

Hi All

What exactly is the difference between below two statements

String s="something";

AND

String s=new String("something");

[Winston Gutkowski]

deepak carter wrote:What exactly is the difference between below two statements
String s="something";
AND
String s=new String("something");

Effectively, nothing. Why do you ask?

Winston

[Manoj Kumar Jain]

As such I don't think there is a difference. but when you use the String as primitive then compiler might create a single String object for many references (if those are having same value) but if you create object with new keyword then they will initialized in different memory location, look at below code:

public class Testvariables  {
	

	public static void main(String [] g)
	{
		String s1=new String("string");
		String s2=new String("string");
		String s3="string";
		String s4="string";
		System.out.println(s1==s2);
		System.out.println(s3==s4);
	}
	
}

[Edit]
below is the output:
false
true

[deepak carter]

I gave an interview yesterday...

He told me that first statement create one object and second statement create two object.

[dennis deems]

The first statement may not actually create any new objects. The second statement will always create at least one new object.

[deepak carter]

what should be the answer...?

[fred rosenberger]

The first time we see a string literal, a String object is created in the String pool. So, the line

String s="something";

may or may not create an object, depending on whether "something" has already been seen.

Now,

String s=new String("something");

uses the new operator. that mean that no matter what, a new object will be created. It uses the literal "something" as a seed to create the object. If "something" has not yet been seen, then we first have to create it on the string pool, and then create the object as per the new operator.

[Winston Gutkowski]

deepak carter wrote:what should be the answer...?

The answer should be the correct one.
While we all suspect what this question is about, you haven't told us what you think it's about...and at the end of the day, that's what is most important.

Winston

[deepak carter]

Hi

If "something" is not seen before


then

String s="something" will create 1 object

and second statement

String s=new String("something");

will create 2 object....

Am I right???

[Winston Gutkowski]

deepak carter wrote:If "something" is not seen before...

Why are you worried? Programs should always do the same (or at least a predictable) thing.

My tip: ALWAYS, ALWAYS, ALWAYS, use equals() with reference variables (and that includes Strings). Only use '==' with primitives.

Winston

[deepak carter]

can i ask you one another question in same thread.

[Winston Gutkowski]

deepak carter wrote:can i ask you one another question in same thread.

If it's related to your previous question, sure; if not, better start a new Thread.

Winston

[Jeff Verdegan]

deepak carter wrote:Hi

If "something" is not seen before


then

String s="something" will create 1 object

No. Executing that line never creates an object. The String object "something" is put into the constant pool when the class is initialized, if it wasn't already there. Before we can execute that line, the String object already exists. That line just gives us a reference to it.

[Jeff Verdegan]

Manoj Kumar Jain wrote:when you use the String as primitive

Which you can never do in Java, since Java Strings are not primitives.

[Jeff Verdegan]

deepak carter wrote:

He told me that first statement create one object and second statement create two object.

First one creates zero objects. Second one creates one String object, and one char[] object. Possibly others, depending on what other members String has--no objects that I know of, but I can't be bothered to look it up.

(I hate it when interviewers give these "clever, tricky technical questions" when they don't even know the right answers themselves.