[英]How to use ternary operator instead of if-else in PHP
I'm trying to shorten my code using the ternary operator. 我正在尝试使用三元运算符来缩短代码。
This is my original code: 这是我的原始代码:
if ($type = "recent") {
$OrderType = "sid DESC";
} elseif ($type = "pop") {
$OrderType = "counter DESC";
} else {
$OrderType = "RAND()";
}
How can I use the ternary operator in my code instead of if
s/ else
s? 如何在代码中使用三元运算符而不是if
s / else
s?
$OrderType = ($type = "recent") ? "sid DESC" : "counter DESC" ;
This is the code I tried, but have no idea how to add an “ elseif
part” to it. 这是我尝试过的代码,但不知道如何向其中添加“ elseif
部分”。
This is called the ternary operator ;-) 这称为三元运算符 ;-)
You could use two of those : 您可以使用其中两个:
$OrderType = ($type == 'recent' ? 'sid DESC' : ($type == 'pop' ? 'counter DESC' : 'RAND()'))
This can be read as : 可以理解为:
$type
is 'recent'
如果$type
是'recent'
'sid DESC'
然后使用'sid DESC'
$type
is 'pop'
如果$type
是'pop'
'counter DESC'
然后使用'counter DESC'
'RAND()'
否则使用'RAND()'
A couple of notes : 一些注意事项:
==
or ===
; 您必须使用==
或===
; and not =
而不是=
()
, to make things easier to read 最好使用()
,使内容更易于阅读
And, as a reference about the ternary operator, quoting the Operators section of the PHP manual : 并且,作为三元运算符的参考,引用PHP手册的Operators部分 :
The third group is the ternary operator:
?:
. 第三组是三元运算符:?:
。
It should be used to select between two expressions depending on a third one, rather than to select two sentences or paths of execution. 应该使用它根据第三个表达式在两个表达式之间进行选择,而不是选择两个语句或执行路径。
Surrounding ternary expressions with parentheses is a very good idea. 用括号括起三元表达式是一个好主意。
I'd suggest using a case statement instead. 我建议改用case语句。 it makes it a little more readable but more maintainable for when you want to add extra options 当您要添加其他选项时,它使它更具可读性,但更易于维护
switch ($type)
{
case "recent":
$OrderType = "sid DESC";
break;
case "pop":
$OrderType = "counter DESC";
break;
default:
$OrderType = "RAND()";
}
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