Question

I am new to programming, but I have a need to group by elements, if they are selected by user; therefore, I am not exactly sure how many elements my group by will contain.
Therefore I did this to count amount of selected elements and then, created another statement that creates correct Group by statement that represents the amount of elements needed.

It works, but it looks bulky and I would like to see if there are better ways of doing this?

int totalOutPuts = 0;
totalOutPuts = endbox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = coursebox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = departmentbox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = callbox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = daybox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = startbox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = instructorbox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = roombox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = buildingbox == true ? totalOutPuts + 1 : totalOutPuts;
totalOutPuts = numberenrolled == true ? totalOutPuts + 1 : totalOutPuts;
int missingElements = 10 - totalOutPuts;

String groupBy = " Group by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10";
if (missingElements == 9) {
    groupBy = " Group by 1";
} else if (missingElements == 8) {
    groupBy = " Group by 1, 2";
} else if (missingElements == 7) {
    groupBy = " Group by 1, 2, 3";
} else if (missingElements == 6) {
    groupBy = " Group by 1, 2, 3, 4";
} else if (missingElements == 5) {
    groupBy = " Group by 1, 2, 3, 4, 5";
} else if (missingElements == 4) {
    groupBy = " Group by 1, 2, 3, 4, 5, 6";
} else if (missingElements == 3) {
    groupBy = " Group by 1, 2, 3, 4, 5, 6, 7";
} else if (missingElements == 2) {
    groupBy = " Group by 1, 2, 3, 4, 5, 6, 7, 8";
} else if (missingElements == 1) {
    groupBy = " Group by 1, 2, 3, 4, 5, 6, 7, 8, 9";
}

Answer 1

Loops! Here’s an implementation suggestion:

// adding all the vars to an array might improve readability
boolean checks[] = new boolean[] { endbox, coursebox, departmentbox, callbox,
                                   daybox, startbox, instructorbox, roombox,
                                   buildingbox, numberenrolled };

for (boolean check : checks) {
    if (check) {
        totalOutPuts++;
    }
}

String groupBy = " Group by ";

// this isn't the best way of appending strings in Java,
// you'd be better using StringBuilder. this is for the sake of simplicity
for (int i = 1; i < totalOutPuts; i++) {
    groupBy += i + ", ";
}

// append the last number
groupBy += totalOutPuts + "";