title: Is this the correct way to use an IllegalArgumentException?
body: <p>I'm trying to work on a Java assignment. This is what it asks:</p>
  
  <blockquote>
    <p>Write a class named <code>TestScores</code>. The class constructor should accept an array of the test scores as its argument. The class should have a method that returns the average of the test scores. If an test score in the array is negative or greater than 100, the class should throw an <code>IllegalArgumentException</code>. Demonstrate. I need a file named <code>TestScores</code> and <code>TestScoresDemo</code>.</p>
  </blockquote>
  
  <p>This is what I have so far. I know some of it is wrong and I need help fixing it:</p>
  
  <pre><code>class TestScores {
      public static void checkscore(int s) {
          if (s&lt;0) throw new IllegalArgumentException("Error: score is negative.");
          else if (s&gt;100) throw new IllegalArgumentException("Error Score is higher then 100");
          else if (s&gt;89)throw new IllegalArgumentException("Your grade is an A");
          else if (s&gt;79 &amp;&amp; s&lt;90)throw new IllegalArgumentException("Your grade is an B");
          else if (s&gt;69 &amp;&amp; s&lt;80)throw new IllegalArgumentException("Your grade is an C");
          else if (s&gt;59 &amp;&amp; s&lt;70)throw new IllegalArgumentException("Your grade is an D");
          else if (s&lt;60)throw new IllegalArgumentException("Your grade is an F");
  
          {
              int sum = 0; //all elements together
              for (int i = 0; i &lt; a.length; i++)
                  sum += a[i];
          }
          return sum / a.length;
      }
  }
  
  class TestScoresDemo {
      public static void main(String[] args) {
          int score = 0;
          Scanner scanner = new Scanner(System.in);
          System.out.print(" Enter a Grade number: ");
          String input = scanner.nextLine();
          score = Integer.parseInt(input);
          TestScores.checkscore(score);
          System.out.print("Test score average is" + sum);
      }
  }
  </code></pre>
  
  <p>I know the assignment calls for a <code>try</code> statement because in my book that's what I see with the <code>IllegalArgumentException</code>. Can anyone help me? I'm using Eclipse as an IDE.</p>