title: Convert a string containing a number in scientific notation to a double in PHP
body: <p>I need help converting a string that contains a number in scientific notation to a double.</p>
  
  <p>Example strings:
  "1.8281e-009"
  "2.3562e-007"
  "0.911348"</p>
  
  <p>I was thinking about just breaking the number into the number on the left and the exponent and than just do the math to generate the number; but is there a better/standard way to do this? </p>