title: difference between $a==5 and 5==$a in php
body: <p>Today I have faced a question, I was unable to answer it, 
  I have tried by making a php program but was unable to find out the exact reason for it 
  if $a=5 then both($a==5 and 5==$a) are giving me output as boolean true and,
  if $a != 5 then both ($a==5 and 5==$a ) are giving me output as boolean false
  <strong>Can anyone tell me what is the difference between $a==5 and 5==$a from any language point of view.</strong></p>
  
  <pre><code>**Program**
  $a = 3;
  var_dump( 5==$a );
  var_dump( $a==5 );
  $a = 5;
  var_dump( 5==$a );
  var_dump( $a==5 );
  
  
  **Output**
  boolean false
  
  boolean false
  
  boolean true
  
  boolean true
  </code></pre>