Philip Drach - 1 year ago 114
Java Question

# How can I represent a boolean type as it's relative integer?

I am practicing my Java and working on a program that will sum up all of the integers from 1 to 999 that are either a multiple of 3 or a multiple of 5.

Here is what I've written so far:

``````public class MultiplesOfThreeAndFive {

public static void main(String[] args) {
//For a number to be a multiple, i % number equals 0.
MultiplesOfThreeAndFive m = new MultiplesOfThreeAndFive();
for (int i = 1; i < 1000; i++){
System.out.println(m.checkIfMult(i));
}
}

public boolean checkIfMult(int i){
return (i % 3 == 0 || i % 5 == 0);
}
}
``````

Now when I compile this, all I get is true and false for each number from 1 to 999. I understand that this is because my method return type for my

``````checkIfMult
``````

method is boolean.

I can't sum up true and false so I want to only acquire those numbers that display as true in the list.

EDIT:

Going by what Tom said...I added this to my main method:

``````    public static void main(String[] args) {
//For a number to be a multiple, i % number equals 0.
MultiplesOfThreeAndFive m = new MultiplesOfThreeAndFive();
for (int i = 1; i < 1000; i++){
System.out.println(m.checkIfMult(i));
if (m.checkIfMult(i) == true){
}
}
}
``````

You can keep a running sum like this:

``````public class MultiplesOfThreeAndFive {

public static void main(String[] args) {
//For a number to be a multiple, i % number equals 0.
MultiplesOfThreeAndFive m = new MultiplesOfThreeAndFive();

int sum = 0;
for (int i = 1; i < 1000; i++){
if (m.checkIfMult(i))
{
sum = sum + i;
}
}
System.out.println("Sum is: " + sum);
}

public boolean checkIfMult(int i){
return (i % 3 == 0 || i % 5 == 0);
}
}
``````

Side Note: You can make the `checkIfMult` method static in this example. If you do so, then you don't need to create an instance of the `MultiplesOfThreeAndFive` class.

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