Output of this character array java program

Question

I am trying to change the information in create a new character array of Str without the whitespaces. However, I cant succeed in doing sp

I dont know why the output says:

Haveaniceday
Have a nice day

instead of:

Haveaniceday
Haveaniceday

import java.util.*;
class DelExtraSpace
{
    public static void main(String args[])
    {
        char c[],s[];
        String str; 
        Scanner scn = new Scanner(System.in);

        str = "Have  a nice   day";

        c = str.toCharArray();
        s = new char [c.length];

        for(int i = 0; i < c.length; i++)
        {
            if(!Character.isSpaceChar(c[i]))
            {
                System.out.print(c[i]);
                s[i] = c[i]; // I want the value of c[i] to be assigned to s[i] only when c[i] is not a whitespace
            }               
        }
        System.out.println();
        for(int j = 0; j < s.length; j++)
            System.out.print(s[j]);
    }
}

Answer 1

I suppose that you are wondering why s is not changed.

In this case, try this:

public static void main(String args[]) {
    char c[], s[];
    String str;
    Scanner scn = new Scanner(System.in);

    str = "Have  a nice   day";

    c = str.toCharArray();
    s = new char[c.length];

    int ii = 0;                                 // ADDED
    for (int i = 0; i < c.length; i++) {
        if (!Character.isSpaceChar(c[i])) {
            System.out.print(c[i]);
            s[ii] = c[i];                       // CHANGED                              
            ii++;                               // ADDED
        }
    }
    System.out.println();
    for (int j = 0; j < s.length; j++)
        System.out.print(s[j]);
}

I added 3 comments for the modified/added lines.

Now the output should be:

Haveaniceday
Haveaniceday

---

Short explanation

Obviously, s will be shorter than c (because it doesn't contain those spaces). This is why you need a new contor (ii) instead of i.

• ii takes values from 0 to 11
• i takes values from 0 to 17

ii -> i
0 -> 0
1 -> 1
2 -> 2
3 -> 3
                 // 4 and 5 are indexes for spaces => they are ignored
4 -> 6           
                 // 7 is index for space => it is ignored
5 -> 8            
6 -> 9
7 -> 10
8 -> 11
                 // 12, 13 and 14 are indexes for spaces => they are ignored
9 -> 15
10 -> 16
11 -> 17

E.g.: When 4 and 5 were ignored, ii was not incremented because we don't need "gaps" in the final array, only the values that are not space.