PHP 运算符“?"是什么?和“:"打电话，他们做什么?
什么是 ? 和 : PHP 中的操作符?
What are the ? and : operators in PHP?
例如:
(($request_type == 'SSL') ? HTTPS_SERVER : HTTP_SERVER)
推荐答案
这是条件运算符.
$x ? $y : $z
表示如果$x为真，则使用$y；否则使用$z".
means "if $x is true, then use $y; otherwise use $z".
它也有一个简短的形式.
It also has a short form.
$x ?: $z
表示如果$x为真，则使用$x；否则使用$z".
means "if $x is true, then use $x; otherwise use $z".
人们会告诉你 ?: 是三元运算符".这是错误的.?: 是 a 三元运算符，也就是说它有三个操作数.人们最终认为它的名字是三元运算符"，因为它通常是给定语言唯一的三元运算符.
People will tell you that ?: is "the ternary operator". This is wrong. ?: is a ternary operator, which means that it has three operands. People wind up thinking its name is "the ternary operator" because it's often the only ternary operator a given language has.
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