Php operators
From wikinotes
$var === NULL // is instance
$var !== NULL // is not instance
$var = 1 // equal
$var != 1 // not equal
$var .= "bar" // append to string
$var += 1; // add 1
$var === NULL // is instance
$var !== NULL // is not instance
$var = 1 // equal
$var != 1 // not equal
$var .= "bar" // append to string
$var += 1; // add 1