在PHP三元速记运算符中使用isset（）时获取变量的值

Question

In using the shorter ternary operator:

$foo = isset($_GET['bar']) ?: 'hello';

If $_GET['bar'] is set, is it possible for $foo to return the value of $_GET['bar'] instead of true?

Edit: I understand the old school ternary works e.g.,

$foo = isset($_GET['bar']) ? $_GET['bar'] : 'hello';

but I want to use the newschool ternary which is the even shorter version

Answer 1

It sounds like you are asking about the new (as of PHP 7) null coalesce operator. You can do something like:

$foo = $_GET['bar'] ?? 'hello';
echo $foo;

Which if $_GET['bar'] is null will set $foo to hello.

The first operand from left to right that exists and is not NULL. NULL if no values are defined and not NULL. Available as of PHP 7.

Functional demo: https://3v4l.org/0CfbE

$foo = $_GET['bar'] ?? 'hello';
echo $foo . "
";
$_GET['bar'] = 'good bye';
$foo = $_GET['bar'] ?? 'hello';
echo $foo;

Output:

hello
good bye

Additional reading on it: http://www.lornajane.net/posts/2015/new-in-php-7-null-coalesce-operator