title: "If" function (js). Syntactic advice required for beginner
body: <p>This is a part of a googlescript i am creating. Please have a look, in the if condition if I have to check for a variable having any of the 2 given values (1 or 0) then is the correct way?</p>
  
  <p><code>if (emailSent != EMAIL_SENT &amp;&amp; emailAddress != '' &amp;&amp; daysleft == 1 &amp;&amp; daysleft == 0) { //</code> </p>
  
  <p>Prevents sending sending same mail again to a person, also skips blank cells</p>
  
  <blockquote>
    <p>//if daysleft =1 or 0 then send mail .</p>
  </blockquote>