title: Dynamically change size of char variable
body: <p>i want to use a string or char variable that size can change dynamically. don't need to specify size and in code can add a cell and insert new char into cell. i use this code for this action:<br/> 
      <code>char *align_A = (char*)malloc(lenMax*sizeof(char));</code><br/>
  is there another way that i don't need to specify size (in here <code>lenMax</code>) and when i want add new char to array or memory, dynamically add a cell and insert char character into. can i use <code>string</code> for this action? <br/>for example: first add into alignA, <code>A</code> character, for next character <code>B</code> size of memory or array changed and add B into and ...  </p>