problems while using modulus (%)

Question

class IfElse
{
    public static void main (String[] args) throws java.lang.Exception
    {
        double x = 1784;

        while (x <= 1){

            if((x % 2) = 0){

                x = x / 2;
            }
            else{
                x = 3 * x + 1;
            }
            System.out.println(x);
        }
    }
}

well, I am having problems with the % (modulus). Could someone help? I am a begginer at coding. Have no idea what I am doing. If someone could help´with this...

You need to be more specific about problems you are facing with this code. Post error message so others with same problems would be also able to find your question and potential answers. Use [edit] option to clarify your question. — Pshemo, May 10 '18 at 19:33

score 0 · Answer 1 · answered May 10 '18 at 19:13

There's a couple issues:

Your while loop (since x is initially set to 1784, but your while loop only runs while x is less than or equal to 1. I think you're going to want to swap those two values around, assuming you want to start at 1 and end when it hits or exceeds 1784.
Additionally, when you're evaluating equality between two values you need to use == rather than a single =. One = assigns a value, the == does an equality comparison and returns a true or false.

Here's additional resources on the equality & relational operators in Java: https://docs.oracle.com/javase/tutorial/java/nutsandbolts/op2.html As well as information on loop control in Java: https://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html

score 0 · Answer 2 · answered May 10 '18 at 19:18

First off your loop will never be entered because 1784 is not less than or equal to 1. Also you need to check equality using == not =. Additionally word of advice, it is strongly recommended that you not use doubles for comparison as rounding can lead to unpredictable results. I would advice you to change double x to int x, unless you are required to use a double.

problems while using modulus (%)

2 Answers2