[JAVA] help with array of strings

[silver calc]

I've been trying to create an array of strings in Java. Here's my code (only the parts giving me problems):

In Class A:

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public class A{
 private String a[10];

 public void changeElement(String e, int num){
  a[num]=e;
 }

}

Here's my application code:

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import Java.util.Scanner;
public class App{
 Scanner reader=new Scanner(System.in);
 System.out.print("Elements(less than 10):");
 int j=reader.nextInt();
 A test=new A();
 for(int i=0; i<j; i++){
  While(reader.nextLine()=="\n");
  System.out.print("\nInput element "+i+":");
  A.changeElement(reader.nextLine(),i);
 }
}

What's wrong with this? It compiles fine, but throws a runtime error pointing to changeElement when I when I try to run this code and it reaches that point.

[threefingeredguy]

What's the error?
I don't think System.in is enough for that to read a string. I think it's got to be

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BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

but I don't know what the Scanner class is, so I can't say that's the problem for sure.

[crzyrbl]

May, or may not help:

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import java.io.*;
public class UserInput
{
  private BufferedReader input = null;

  public UserInput()
  {
       input = new BufferedReader(new InputStreamReader(System.in));

  }

  public String getValue(String question) throws IOException
  {
       System.out.print(question);
       String answerStr = input.readLine();
	   return answerStr;
  }

}

[silver calc]

Huh? What version of java are you using?

In the newer versions there is a scanner class that deals with input. I just want to know how to take user input and put it into a String array.

[anykey]

It looks fine to me.
Perhaps you should use an arraylist? I find them quite enjoyable.
oh, and changeElement should probably be renamed addElement, or maybe just add.
I'm glad I could not help.

[silver calc]

nevermind, i figured it out. turns out that initializing arrays in java are different:
C++ way:

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char array[maxsize][5];    //max size is a large number so that the string doesn't run out of space

Java way:

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String[] array = new String[5];

[coelurus]

What compiler are you using? You should get a compiler error because that syntax is simply not valid in Java.

[benryves]

Yes, I thought it odd that Java used the strange and rather non-intuitive array declaration syntax from C. I'm glad it doesn't.

That top example is not the C++ way. If you think it is, take a look at std::string instead of char arrays (which are, unfortunately, the C way).

[Spencer]

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char array[5][maxsize];

[crzyrbl]

oh ya, I forgot about that. I haven't used Java in a while.