In PHP, what does the 'at' symbol before an L-value mean?

Question

Everything I can find refers to the use of the @ symbol as a prefix to an expression, e.g.:

$foo = @bar();

This is not what I'm talking about here. I have a statement which uses the @ symbol as a prefix to an L-value, like:

@$foo = bar();

What does this mean?

(Ideally, please explain the semantics as a de-sugaring of this statement into one that does not use the @ symbol.)

Answer 1

@ symbol is used to suppress error messages

PHP supports one error control operator: the at sign (@). When prepended to an expression in PHP, any error messages that might be generated by that expression will be ignored.

For example;

The following code doesn't produce any errors on screen;

<?php

ini_set('error_reporting', E_ALL);
ini_set('display_errors', 1);

@$foo = $bar;

echo $foo;

However, without the @ it does;

Notice: Undefined variable: bar in C:\xampp\htdocs\test\test.php on line 6