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    <p>You made 2 mistakes. The first is explained in the comment by <a href="https://stackoverflow.com/a/16726622/624041">@Thomas</a> and the second is explained in the comment by <a href="https://stackoverflow.com/a/16726635/624041">@rolfl</a>. I corrected them both here:</p> <pre><code>public class PrimeNumber extends ConsoleProgram { public void run() { for (int i = 50; i &gt;= 2; i--) { boolean isPrime = true; for (int j = 2; j &lt; i-1; j++) { //increment "j" not "i" if (i % j == 0) { isPrime = false; break; } } if (isPrime) System.out.println(i); } } } </code></pre> <p>Note: I verified the solution using this code (save in your IDE as PrimeNumber.java):</p> <pre><code>public class PrimeNumber { public static void main (String args[]) { for (int i = 50; i &gt;= 2; i--) { boolean isPrime = true; for (int j = 2; j &lt; i-1; j++) { //increment "j" not "i" if (i % j == 0) { isPrime = false; break; } } if (isPrime) System.out.println(i); } } } </code></pre> <hr> <p><strong>Edit:</strong> For your understanding, your main problem is the logic here:</p> <pre><code>for (int j= 2; j &lt; i-1; j++) { if (i % j &gt;= 1) { println(i); </code></pre> <p>You are printing <code>i</code> after only checking one possibility. </p> <p>For example, take <code>i = 7</code>. You have to test <code>i % j</code> for <code>j</code> = 6, 5, 4, 3, and 2 before you can say that <code>i</code> is prime. You can't just test <code>i % j</code> for <code>j = 6</code>, as you have done. To do so, your <code>println</code> statement should come after the for loop, not nested inside of it, so you can test all the possible values of <code>j</code> first.</p> <hr> <p><strong>Edit 2:</strong> In response to</p> <blockquote> <p>Coincidentally enough, the 1st part of the assignment is to write a predicate method that returns true if the number is prime and false if it is not prime using the strategy of brute-force. The 2nd part of the assignment is to find a more efficient way and reworking the 1st part of the assignment to be more efficient. I was trying to solve the problem using just using two for loops to see if i could do it. Can it be done with just two for loops w/o label and continue since my book has not covered that yet?</p> </blockquote> <p>Try something like this:</p> <pre><code>public boolean isPrime(int number) { for (int i = 2; i &lt; number; i++) { if (number % i == 0) { return false; //not prime } } return true; //prime } </code></pre>
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    1. POBrute force method finding prime numbers
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    1. COthanks a lot. I'm still studying and experimenting with all the answers. Your answer makes a lot of sense.
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    2. CONo problem. See my edit for a bit more.
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    3. COthanks for all the help. I really appreciate it. Your answers have really helped me a lot.
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