比较 PHP 中的多个值
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Compare multiple values in PHP
提问by John
I'd like to go from this:
我想从这个开始：
if($var == 3 || $var == 4 || $var == 5 || $var =='string' || $var == '2010-05-16') {
// execute code here
}
to this:
对此：
if($var == (3, 4, 5, 'string', '2010-05-16')) { // execute code here }
Seems very redundant to keep typing $var, and I find that it makes it a bit cumbersome to read. Is there a way in PHP to do simplify it in this way? I read on a post here that when using XQuery you can use the = operator as in $var = (1,2,3,4,5)etc.
继续打字似乎很多余$var，而且我发现阅读起来有点麻烦。PHP中有没有办法以这种方式简化它？我在这里读到一篇文章，当使用 XQuery 时，您可以使用 = 运算符$var = (1,2,3,4,5)等。
回答by Greg
Place the values in an array, then use the function in_array() to check if they exist.
将值放入数组中，然后使用函数 in_array() 检查它们是否存在。
$checkVars = array(3, 4, 5, "string", "2010-05-16");
if(in_array($var, $checkVars)){
// Value is found.
}
回答by NikiC
If you need to perform this check very often and you need good performance, don't use a slow array search but use a fast hash table lookup instead:
如果您需要经常执行此检查并且需要良好的性能，请不要使用慢速数组搜索，而是使用快速哈希表查找：
$vals = array(
1 => 1,
2 => 1,
'Hi' => 1,
);
if (isset($vals[$val])) {
// go!
}
回答by tdammers
if (in_array($var, array(3, 4, 5, 'string', '2010-05-16'))) {execute code here }
Or, alternatively, a switch block:
或者，或者，一个开关块：
switch ($var) {
case 3:
case 4:
case 5:
case 'string':
case '2010-05-16':
execute code here;
break;
}
回答by Pekka
You can use in_array().
您可以使用in_array().
if (in_array($var, array(3,4,5,"string","2010-05-16"))) { .... }
回答by MatTheCat
Or you can use in_array()
或者你可以使用 in_array()
if(in_array($var,array(4,5,'string','2010-05-16',true)) {
}
回答by AbcAeffchen
Just to give an alternative solution to the use of in_array:
只是为了提供使用的替代解决方案in_array：
In some cases it could be faster to set an array where the values are keys and then check with isset()
在某些情况下，设置值是键的数组可能会更快，然后检查 isset()
Example:
例子：
$checkVars= [3 => true,
4 => true,
5 => true,
"string" => true,
"2010-05-16" => true];
if(isset($checkVars[$var])
{
// code here
}
EDIT: I have done some testing and it looks like this method is faster in most cases.
编辑：我已经做了一些测试，看起来这种方法在大多数情况下更快。
回答by Andrew Sledge
$vals = array (3, 4, 5, 'string', '2010-05-16');
if(in_array($var, $vals)) {
//execute code here
}
回答by Andrew Sledge
I've had this problem and solved it by making this function:
我遇到了这个问题并通过创建这个函数来解决它：
function orEquals(){
$args = func_get_args();
foreach($args as $arg){
if ($arg != $args[0]){
if($arg == $args[0]){
return true;
break;
}
}
}
unset($args);
}
then you can just call the function like this:
那么你可以像这样调用函数：
if(orEquals($var, 3, 4, 5, 'string', '2010-05-16')){
//your code here
}
