Quiz Time

[sanjeevtarar]

I think it will print "NO"....

[rjuyal]

let us know the correct answer

@sanjeev

why do you think it will print No, is this only because it is posted in Quiz section

[Eranga]

Ok, the answer is Yes.

So I post a big banana to Delhi.

Here is the thing I want to point there, I really hate that code. Because == used for string comparison. Not a good practice at all. Because '==' operator compares two object references and check whether two objects are exactly the same object or not.

Should I put an example, in that case I really need a gift.

[Eranga]

Need any more explanations.

[sanjeevtarar]

Quote:

Originally Posted by rjuyal

let us know the correct answer

@sanjeev

why do you think it will print No, is this only because it is posted in Quiz section

No dear......It doesn't mean this.
If we are doing practice by this way it is good for us.....


I guessed It.....may be two different "String" will be created in Heap.....
that's why i said no....because == checks for reference.

[sanjeevtarar]

Well Eranga....

again good question....

[rjuyal]

yes, certainly

why it was in Quiz section lol

what about

==, even if we use,
equals/equalsIgnoreCase/contentEqual

we will get the same answer "YES"

so, what was the question,

Or simply can you give us an example where
"==" is different from "equals"

[rjuyal]

Code:

I guessed It.....may be two different "String" will be created in Heap.....
that's why i said no....because == checks for reference.

Strings are interned

[Eranga]

Still there are lots of points to talk. May be not for us, for newbie specially.

Ok, Sanjeev and Rakesh, can you the difference about those two line of code.

Code:

if("String".trim() == "String".trim())

and

Code:

if("String".trim() == "String      ".trim())

Did you see the slight difference there. My next quiz is, the answer is changed or remain as "Yes"?

[Eranga]

Quote:

Originally Posted by rjuyal

Or simply can you give us an example where
"==" is different from "equals"

A BIG difference in real world application pal.

[sanjeevtarar]

Quote:

Originally Posted by rjuyal

yes, certainly

why it was in Quiz section lol

what about

==, even if we use,
equals/equalsIgnoreCase/contentEqual

we will get the same answer "YES"

so, what was the question,

Or simply can you give us an example where
"==" is different from "equals"

Check It

Code:

public class EqualsCheck {
    
    public static void main(String[] args) {

		String s = "Hello";
		String s1 = "Hello";
		String s2 = new String("Hello");
		
		if(s == s1)
			System.out.println("Yes, ==");
		else
			System.out.println("No, ==");

		if(s == s2)
			System.out.println("Yes, ==");
		else
			System.out.println("No, ==");

		/******************************/
		if(s.equals(s1))
			System.out.println("Yes, equals()");
		else
			System.out.println("No, equals()");

		if(s.equals(s2))
			System.out.println("Yes, equals()");
		else
			System.out.println("No, equals()");
		/******************************/

    }
}

[sanjeevtarar]

Quote:

Originally Posted by Eranga

Still there are lots of points to talk. May be not for us, for newbie specially.

Ok, Sanjeev and Rakesh, can you the difference about those two line of code.

Code:

if("String".trim() == "String".trim())

and

Code:

if("String".trim() == "String      ".trim())

Did you see the slight difference there. My next quiz is, the answer is changed or remain as "Yes"?

Ans will be YES ...... because trim() method will be called first

[rjuyal]

You will get you banana back as your gift, if you give us the example

Using String, use '==' and 'equals' but answer should be different.

Please sanjeev, if you have some example then post it here

Code:

if("String".trim() == "String      ".trim())

i guess the answer should be same again.

Both will become "String" after trimming, and as String are interned both will have same reference.

[Eranga]

Quote:

Originally Posted by sanjeevtarar

Ans will be YES ...... because trim() method will be called first

No, you are wrong. Because trim() not will effect with '==' operators. That one of the deprecate process take place by Suns'

If you do it as follows,

Code:

        if("String".equals("String    ".trim()))
            System.out.println("Yes");
        else
            System.out.println("No");

Your answer is "Yes". trim() do the omitting white spaces perfectly.

[sanjeevtarar]

Quote:

Originally Posted by rjuyal

You will get you banana back as your gift, if you give us the example

Using String, use '==' and 'equals' but answer should be different.

Please sanjeev, if you have some example then post it here

Code:

if("String".trim() == "String      ".trim())

i guess the answer should be same again.

Both will become "String" after trimming, and as String are interned both will have same reference.

Rakesh.....see example in reply #31

[rjuyal]

Code:

public class EqualsCheck {
    
    public static void main(String[] args) {

		String s = "Hello";
		String s1 = "Hello";
		String s2 = new String("Hello");
		
		if(s == s1)
			System.out.println("Yes, ==");
		else
			System.out.println("No, ==");

		if(s == s2)
			System.out.println("Yes, ==");
		else
			System.out.println("No, ==");

		/******************************/
		if(s.equals(s1))
			System.out.println("Yes, equals()");
		else
			System.out.println("No, equals()");

		if(s.equals(s2))
			System.out.println("Yes, equals()");
		else
			System.out.println("No, equals()");
		/******************************/

    }
}

Wow... i wanted this actually

Thanks Sanjeev

[sanjeevtarar]

Quote:

Originally Posted by Eranga

No, you are wrong. Because trim() not will effect with '==' operators. That one of the deprecate process take place by Suns'

If you do it as follows,

Code:

        if("String".equals("String    ".trim()))
            System.out.println("Yes");
        else
            System.out.println("No");

Your answer is "Yes". trim() do the omitting white spaces perfectly.

Hey Eranga

Really ....... It's important point.

askkkkkkkkkkkkkkkkkk morreeeeeeeeeee dear..

[sanjeevtarar]

Quote:

Originally Posted by rjuyal

Wow... i wanted this actually

Thanks Sanjeev

It's Ok Rakesh.

Do you really know how both (== and equals()) are working and why output is different. Give some thoughts and then explain here.

[Eranga]

Seems that I got my banana back,

Here is an example I came to mind in a second.

Code:

public class WhisIsTheBest {

    public static void main(String[] args) {
        
        String strObjOne = new String("String");
        String strObjTwo = new String("String");
        String strObjThree = strObjOne;
 
        System.out.println("String 1 is " + strObjOne);
 
        System.out.println("String 2 is " + strObjTwo);
 
        System.out.println("String 3 is " + strObjThree);
 
        System.out.println(strObjThree == strObjOne);
 
        System.out.println(strObjThree == strObjTwo);
        System.out.println(strObjThree.equals(strObjTwo));
    }
}

What did you say now pal.

[Eranga]

See my String object behaviors.