Java String Array Iteration: Is there any way to make this simpler?

Question

Good day,

I'm new to Java and have been practicing with Nested Loop iterations. I was wondering if there is any simpler way on how to do this? Especially on the part where I had to put this [j+1].

String[][] entry = {{"010", "John", "Male", "21"},
                {"011", "Mary", "Female", "25"},
                {"012", "Joseph", "Male", "24"},
                {"013", "Peter", "Male", "22"}};


for ( int i = 0; i < entry.length; i++) {

    for ( int j = 0; j < entry[i].length;) {
        System.out.print("ID: " + entry[i][j] + "\n");
        System.out.print("Name: " + entry[i][j+1] + "\n");
        System.out.print("Gender: " + entry[i][j+2] + "\n");
        System.out.print("Age: " + entry[i][j+3] + "\n");
        System.out.println(""); 
        break;
    }           
}

Expected output is like this:

ID: 010
Name: John
Gender: Male
Age: 21

ID: 011
Name: Mary
Gender: Female
Age: 25

ID: 012
Name: Joseph
Gender: Male
Age: 24

ID: 013
Name: Peter
Gender: Male
Age: 22

Your help is highly appreciated!

Answer 1

Erm... You can delete your inner loop, as you are breaking in the first iteration, hence not looping at all.

String[][] entry = { {"010", "John", "Male", "21"},
                     {"011", "Mary", "Female", "25"},
                     {"012", "Joseph", "Male", "24"},
                     {"013", "Peter", "Male", "22"} };


for (int i = 0; i < entry.length; i++) {
    System.out.print("ID: " + entry[i][0] + "\n");
    System.out.print("Name: " + entry[i][1] + "\n");
    System.out.print("Gender: " + entry[i][2] + "\n");
    System.out.print("Age: " + entry[i][3] + "\n");
    System.out.println("");       
}

EDIT: If nested loop is mandatory, you can achieve the same output like so:

String[] type = { "ID", "Name", "Gender", "Age" };

String[][] entry = { {"010", "John", "Male", "21"},
                     {"011", "Mary", "Female", "25"},
                     {"012", "Joseph", "Male", "24"},
                     {"013", "Peter", "Male", "22"} };


for (int i = 0; i < entry.length; i++) {
    for (int j = 0; j < entry[i].length; j++) {
        System.out.println(type[j] + ": " + entry[i][j]);
    }
    System.out.println("");       
}

But, I'd advise against this.

Answer 2

I think this is what you are looking for:

String[][] entry = {{"010", "John", "Male", "21"},
                {"011", "Mary", "Female", "25"},
                {"012", "Joseph", "Male", "24"},
                {"013", "Peter", "Male", "22"}};

String[] label = {"ID", "Name", "Gender", "Age"};

for (int i = 0; i < entry.length; i++) {
    for (int j = 0; j < entry[i].length;) {
        System.out.println(label[j] + ": " + entry[i][j]);
    } 
    System.out.println(); 
}

I have removed the break. It shouldn't have been present in the original code either.

It is better to use println than to append a newline. (Appending \n is not portable. The correct line separator to use is OS dependent. There ways to append the correct line separator, but it is simpler to let println take care of it.)

We could also use printf rather than concatenating the strings explicitly.