title: Evaluate command line argument as boolean expression
body: <p>I'm trying to take a string, passed as an argument, and evaluate it as a boolean expression in an <em>if</em> conditional statement.  For example, the user invokes MyProgram like <code>$ java MyProgram x==y</code>.</p>
  <hr />
  <h4>Example Program</h4>
  <p>Defined variables:</p>
  <pre><code>int x;
  int y;
  </code></pre>
  <p>Boolean expression argument:</p>
  <pre><code>String stringToEval = args[0];
  </code></pre>
  <p>Control program execution with user expression:</p>
  <pre><code>if (stringToEval) {
      ...
  }
  </code></pre>