Array output structure

Question

Why the output of this code is

island = Fiji
island = Cozumel
island = Bermuda
island = Azores

Why the output starts from Fiji island , instead of "Bermuda"? Bermuda have 0 element in array . Can you please point me why my output have such specific order.

public class TestArrays {
public static void main (String[] args){
    int y = 0;
    int[] index = new int [4];
    index[0] = 1;
    index[1] = 3;
    index[2] = 0;
    index[3] = 2;


    String[] islands = new String[4];
    islands[0] = "Bermuda";
    islands[1] = "Fiji";
    islands[2] = "Azores";
    islands[3] = "Cozumel";

    int ref;
    while ( y < 4){
        ref = index[y];
        System.out.print("island = ");
        System.out.println(islands[ref]);
        y = y + 1;

    }

}

As i understand it should be like : Bermuda / Fiji / Azores / Cozumel Each time by adding y+1; — Anton Anton
– Anton Anton, Commented Sep 18, 2016 at 18:49

Raktim Biswas · Accepted Answer · 2016-09-18 19:06:20Z

1

It's quite simple:

ref = index[y];

The above line outputs ref as 1, since index[y] results 1 when y was 0.

Therefore,

ref = 1  //index[0] = 1;

Now, the line below:

System.out.println(islands[ref]);

Outputs:

island = Fiji

because ref was 1 and islands[ref] stands Fiji as in:

islands[1] = "Fiji";

edited Sep 18, 2016 at 19:06

answered Sep 18, 2016 at 18:53

Raktim Biswas

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Comments

Kelvin · Accepted Answer · 2016-09-18 18:51:46Z

0

Your index is ordered as {1, 3, 0, 2}

int[] index = new int [4];
index[0] = 1;
index[1] = 3;
index[2] = 0;
index[3] = 2;

So it will print islands[1], islands[3], islands[0], islands[2]

String[] islands = new String[4];
islands[0] = "Bermuda";
islands[1] = "Fiji";
islands[2] = "Azores";
islands[3] = "Cozumel";

Fiji, Cozumel, Bermuda, Azores

answered Sep 18, 2016 at 18:51

Kelvin

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Hypnic Jerk · Accepted Answer · 2016-09-18 18:52:40Z

0

Basically, it is printing out that way because you are telling it to.

You set up your index like this

int[] index = new int [4];
    index[0] = 1;
    index[1] = 3;
    index[2] = 0;
    index[3] = 2;

and then call

ref = index[y];
        System.out.print("island = ");
        System.out.println(islands[ref]);
        y = y + 1;

The value in index[y] is why you are printing it out in that order.

index[0] is 1, so when you call System.out.println(islands[ref]); you are calling System.out.println(islands[1]);, which is Fiji.

answered Sep 18, 2016 at 18:52

Hypnic Jerk

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Comments

Rishabh Gupta · Accepted Answer · 2016-09-18 18:58:09Z

0

In the call island[ref] for y=0,1,2,3. The calls are

island[index[0]] = island [1] = "Fiji"
island[index[1]] = island [3] = "Cozumel"
island[index[2]] = island [0] = "Bermuda"
island[index[3]] = island [2] = "Azores"

You have basically changed the index call for island from your index array.

answered Sep 18, 2016 at 18:58

Rishabh Gupta

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SSC · Accepted Answer · 2016-09-18 19:11:49Z

0

    int ref;
    while ( y < 4){
        System.out.println(y); (1)
        ref = index[y];
        System.out.println(ref); (2)
        System.out.print("island = ");
        System.out.println(islands[ref]);
        y = y + 1;

    }

Iteration # 01

Statement (1) will produce 0 since y is 0, and statement (2) will produce 1 because index[0] has 1 stored in it. And islands[1] has Fiji

Iteration # 02

Statement (1) will produce 1 since y is 1, and statement (2) will produce 3 because index[1] has 3 stored in it. And islands[3] has Cozumel

Iterating over the while loop like this until y < 4 for each index will help you see, why the generated output is like the way, it is.

answered Sep 18, 2016 at 19:11

SSC

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