title: Insert a character into a string at a specified index
body: <p>So I have an array of indexes of characters in a string that I wish to insert a character before, how do i easily insert a character before each index? So for example:</p>
  
  <p>"The big brown fox ... "</p>
  
  <p>the positions
  array = 4,9</p>
  
  <p>the character to insert ','</p>
  
  <p>the result: "The, big, brown fox ..."</p>
  
  <p>Is there a method that provides such an easy utility?</p>
  
  <p>String.insert(originalStr, index, stringToInsert) for example???</p>
  
  <hr>
  
  <p><strong>Update</strong></p>
  
  <p>The example I provided is just an example implementation. I also may want to do the following:</p>
  
  <p>orginalText = "some text with characters like ; : } &lt;"</p>
  
  <p>in which I may want to insert "\" with the result being:</p>
  
  <p>result = "some text with characters like \; : } \&lt;"</p>