Eclipse 不打印空字符

Question

I'm writing a java program in Eclipse. Lets say I declare an array:

char[] array = new char[5];

and then I initialize only few elements. When I try to print entire array, Eclipse stops when uninitialized element is reached, and does nothing. On the other hand, when I compile it in terminal using javac command, it works just fine, and prints blank spaces for uninitialized elements (or I should say null characters). Why does this happen?

EDIT: here is the full code (the program finds sub array taking only letters from the original one)

public static void main(String[] args) {
    // TODO Auto-generated method stub
    Scanner input=new Scanner(System.in);

    int n=4;
    char[] array=new char[n];
    System.out.println("Input array elements: ");
    for(int i=0; i<n; i++){
        array[i]=input.next().charAt(0);
    }
    char[] A=new char[n];
    int j=0;
    for(int i=0; i<array.length; i++){
        if ((array[i]>=65 && array[i]<=90)||(array[i]>=97 && array[i]<=122)){
            A[j]=array[i];
            j++;
        }

    }

    System.out.printf("subarray is A=[ ");
    for(int i=0; i<n; i++){
            System.out.printf(A[i]+" ");
    }
    System.out.printf("].");
}

for example if input is st1p, it outputs [ stp and stops there. Doesn't execute last print.

Answer 1

Well that is because the default value of a char attribute is '\' (the null character) as stated in the Java Language Specification, section § 4.12.5 Initial Values of Variables .

I have modified and created a small project that converts a word into a string and prints it entirely. It does print numbers as well. I hope this helps you in what you are looking for. Of course then you can create other char arrays and populate each second letter, third etc etc and get an n'th grand total char array with each substring from each word. Just like you did.

 public class stringToArray {

    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);
        System.out.println("Enter string: ");
        String word = input.next();

        int index = word.length(); // get index of word to create array of exact length
        char[] chars = new char[index]; // create the array of exact length

        System.out.print("The char array from the String is: ");
        for (int i = 0; i < chars.length; i++) {
            chars[i] = word.charAt(i); // populate the char array with the word, by breaking the word in chars 

            System.out.print(chars[i] + " "); // print it to check that it is working
        }

    }
}