Core Java - Find the Output

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Core Java | Question 498 of 502

Find the Output

class A{
public static void main(String[] a){
System.out.print(String.valueOf(1)+String.valueOf(2));
String s1="s1";
String s2=s1.toString();
System.out.print(","+(s1==s2));
}
}

Total Answers and Comments: 10

Last Update: October 30, 2009 Asked by: aruneverb4u

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Best Rated Answer

—

Submitted by: priya.java

12 true,

s2=s1.toString(), ref to same object.

if s2=new String(s1);---Object ref will be diffrent , ans ans will be false

Above answer was rated as good by the following members:
ae8166558de88, geeta.jagan

July 21, 2009 21:25:04

myogeshchavan97

Member Since: December 2008 Contribution: 28

RE: Find the Output

The output of this program is 12.
explanation:
String.valueOf() is used to convert to string type.Thus 1 is converted to string and using + sign 2 is concatenated to 1 (after converting 2 to string)
Hence the result.

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July 23, 2009 02:23:45

rave123nitb

Member Since: July 2009 Contribution: 1

RE: Find the Output

12 true

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1 0

Overall Rating: +1

July 27, 2009 03:24:12

mukuldhali

Member Since: June 2009 Contribution: 1

RE: Find the Output

There will be a compiler error if the class A is not public. If the class is public then the out put will be:
12 true

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0 1

Overall Rating: -1

August 12, 2009 03:10:15

Sarje

Member Since: August 2009 Contribution: 62

RE: Find the Output

12 false
false because operator checks reference equality not object content equality and s1 and s2 are two different references.

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August 26, 2009 00:48:42

priya.java

Member Since: August 2009 Contribution: 1

RE: Find the Output

12 true

s2 s1.toString() ref to same object.

if s2 new String(s1);---Object ref will be diffrent ans ans will be false

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1 0

Overall Rating: +1

September 18, 2009 01:45:36

vittal.kv

Member Since: September 2009 Contribution: 1

RE: Find the Output

12 true.

1+2 gives 12 as string values will be appended
and both the string are reffering to same instance

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September 28, 2009 10:32:36

Muthu Kumaran Arunachalam

Member Since: September 2009 Contribution: 1

RE: Find the Output

12 True.
Since the String s1 s2 are String constants and they pointing the same reference in String Constant Pool the
comparison s1 s2 will print true.

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October 14, 2009 19:26:40

vdkrav

Member Since: October 2009 Contribution: 1

RE: Find the Output

12 true

Nobody noticed comma!

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October 21, 2009 05:57:44

ae8166558de88

Member Since: October 2009 Contribution: 3

RE: Find the Output

First SOP is like every one is saying but for second this is what actually written in String class:

public String toString() {
return this;
}

so when compared using ( ) same reference values are compared and it gives true

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October 29, 2009 08:05:59

#10

StewartS

Member Since: October 2009 Contribution: 1

RE: Find the Output

The output is:

12 true

Explanation:
The easy bit is that the first call to print() displays "12".

The Javadoc for String.toString() says the return value is:

"This object (which is already a string!) is itself returned."

So s1 and s2 refer to the same value. This means that the (s1 s2) comparison is true. Therefore the second call to print displays " true".

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