title: Splitting string expression into tokens
body: <p>My input is like</p>
  
  <pre><code>String str = "-1.33E+4-helloeeee+4+(5*2(10/2)5*10)/2";
  </code></pre>
  
  <p>i want the output as:</p>
  
  <pre><code>1.33E+4
  helloeeee
  4
  5
  2
  10
  2
  5
  10
  2
  </code></pre>
  
  <p>But I am getting the output as</p>
  
  <pre><code>1.33, 4, helloeeee, 4, 5, 2, 10, 2, 5, 10, 2
  </code></pre>
  
  <p>i want the exponent value completely after splitting "1.33e+4"</p>
  
  <p>here is my code:</p>
  
  <pre><code>    String str = "-1.33E+4-helloeeee+4+(5*2(10/2)5*10)/2";
      List&lt;String&gt; tokensOfExpression = new ArrayList&lt;String&gt;();
      String[] tokens=str.split("[(?!E)+*\\-/()]+");
      for(String token:tokens)
      {   
           System.out.println(token);
           tokensOfExpression.add(token);
      }
      if(tokensOfExpression.get(0).equals(""))
      {
           tokensOfExpression.remove(0);
      }
  </code></pre>