问题
What does the following code do? A link to something in the PHP manual would also be nice.
if ($_SERVER['SERVER_PORT'] <> 443) {
doSomething();
}
回答1:
Same as !=, "Not equal"
false <> true // operator will evaluate expression as true
false != true // operator will evaluate expression as true
Here is some reference: PHP Comparison Operators
回答2:
It's another way of saying "not equal to" (the != operator). I think of it as the "less than or greater than" operator which really just means "not equal to".
回答3:
It's equivalent to !=:
http://au.php.net/operators.comparison
回答4:
$_SERVER['SERVER_PORT'] gets the port used by the web server to serve HTTP requests. $_SERVER['SERVER_PORT'] <> 443 checks if the port is not equal to 443 (the default HTTPS port) and if not, invokes doSomething()
回答5:
Note that <> behaves as != even where < and > are not obvious comparison operators (eg $str1 <> $str2).
回答6:
Although PHP is mostly based on C-style syntax, this is one of the weird things that comes from the BASIC-style syntax world.
Needless to say, I'd just use != and be consistent with it, as <> is really never used.
来源：https://stackoverflow.com/questions/249312/php-operator