title: How to split string by '+' Except inside square brackets
body: <p>My example string: <code>a+[b*a+c]+c+[ab+c]</code> and split by '+'</p>
  <p>After split:</p>
  <pre><code>a
  [b*a+c]
  c
  [ab+c]
  </code></pre>
  <p>I can do it for parentheses by using <code>\\+(?![^()]*\\))</code> as regex into <code>input.split(regex)</code>. But cant figure out for square brackets. I appreciate for any kind of help</p>