Coverting String to char Array throwing an error - Exception in thread "main" java.lang.NullPointerException

Question

I am Beginner in java ,I am just trying out to convert string into char array,though it is running fine on my System but on a competitive coding website it is throwing an error.Here is the link of that Question Exception in thread "main" java.lang.NullPointerException

Here is my piece of code I have used BufferedReader to take input:-

                String s1;
                s1= inp.readLine();
                String s2;
                s2=s1;
                char ch1[] = s1.toCharArray();
                char ch2[] = s2.toCharArray();

Please help!

Dominik 105 · Answer 1 · 2017-02-02T21:49:20.943

0

You didn't initialize String s1 so its value is null and you get a NullPointerException. Initialize s1 with String s1 = ""; This should already work. Otherwise just use for test case and for the beginning a random value to initialize.

EDIT:

edited Feb 02 '17 at 21:49

answered Feb 02 '17 at 21:36

Dominik 105

74
1
8

No. `s1` is initialised here: `s1= inp.readLine();`. – Jason Feb 02 '17 at 21:38
Yes s1=" "; is not working here – Vinit Raj Feb 02 '17 at 21:40
Then both are initialized and there should not be a problem. That's the only thing I can think of. Maybe `inp.readLine()` gives null. – Dominik 105 Feb 02 '17 at 21:40
Maybe print `inp.readLine()` , if it's null, that may causes the problem – Dominik 105 Feb 02 '17 at 21:41
Yes `inp` is null I guess. Otherwise the code would work. – name not found Feb 02 '17 at 21:41
Actually Code is working and giving the correct output,but still it is giving a run time error.. – Vinit Raj Feb 02 '17 at 21:42
1

Then the error is in some code you are not showing us. If you run it through a debugger, you will see exactly which line is causing the problem. – Jason Feb 05 '17 at 22:00

Coverting String to char Array throwing an error - Exception in thread "main" java.lang.NullPointerException

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