This question already has an answer here:
Can you please tell me the difference between $variable and @$variable in php
<?php
curl function abc
{
get information of url and return information string
}
$html=abc();
$doc=DOMDocument();
@$doc->LoadHTML($html);
?>
here if we take normal variable it gives error why its so and whats the difference
</div>
A @ before a function call means "suppress warnings".
So, @$doc->LoadHTML($html); suppresses warnings from the method call (LoadHTML()).
In general this is a bad idea, because the warnings mean you are doing something wrong, and you would better fix that instead of playing deaf.
The @ operator tells the compiler to ignore the error that PHP could give, its advised not to use it.
Suppress warning when accessing that property, if for instance $html was undefined then no error is displayed, see http://davidwalsh.name/suppress-php-errors-warnings
@ is called Error Control Operator, it can be prepended before expression to disable error reporting for that expression.
Please see this post for more information: Suppress error with @ operator in PHP