[PHP]：如果什么也没找到，array_search() 会返回什么？
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[PHP]: What does array_search() return if nothing was found?
提问by Derek Adair
What does array_search() return if nothing was found?
如果什么也没找到，array_search() 会返回什么？
I have the need for the following logic:
我需要以下逻辑：
$found = array_search($needle, $haystack);
if($found){
//do stuff
} else {
//do different stuff
}
回答by Pascal MARTIN
Quoting the manual page of array_search():
引用手册页array_search()：
Returns the key for needle if it is found in the array,
FALSEotherwise.
如果在数组中找到了针，则返回它的键，
FALSE否则返回。
Which means you have to use something like :
这意味着你必须使用类似的东西：
$found = array_search($needle, $haystack);
if ($found !== false) {
// do stuff
// when found
} else {
// do different stuff
// when not found
}
Note I used the !==operator, that does a type-sensitive comparison ; see Comparison Operators, Type Juggling, and Converting to booleanfor more details about that ;-)
回答by user187291
回答by Jaime Montoya
According to the official documentation at http://php.net/manual/en/function.array-search.php:
根据http://php.net/manual/en/function.array-search.php的官方文档：
Warning This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.
警告 此函数可能返回布尔值 FALSE，但也可能返回计算结果为 FALSE 的非布尔值。请阅读有关布尔值的部分以获取更多信息。使用 === 运算符来测试此函数的返回值。
See this example:
看这个例子：
$foundKey = array_search(12345, $myArray);
if(!isset($foundKey)){
// If $myArray is null, then $foundKey will be null too.
// Do something when both $myArray and $foundKey are null.
} elseif ($foundKey===false) {
// $myArray is not null, but 12345 was not found in the $myArray array.
}else{
// 12345 was found in the $myArray array.
}
回答by oggy
From the docs:
从文档：
Searches haystack for needle and returns the key if it is found in the array, FALSE otherwise.
在 haystack 中搜索 Needle，如果在数组中找到，则返回键，否则返回 FALSE。
回答by ashurexm
array_search will return FALSE if nothing is found. If it DOES find the needle it will return the array key for the needle.
如果未找到任何内容，array_search 将返回 FALSE。如果它确实找到了针，它将返回针的数组键。
More info at: http://php.net/manual/en/function.array-search.php
回答by Basj
One has to be careful to distinguish found, index 0and not found, for this use the !== falsetest. Example:
必须小心区分found, index 0和not found，为此使用!== false测试。例子：
<?php
$array = array(0 => 'blue', 1 => 'red', 2 => 'green', 3 => 'red');
$i = array_search('red', $array);
echo ($i !== false) ? $i : -1; // 1
$i = array_search('blue', $array);
echo ($i !== false) ? $i : -1; // 0
$i = array_search('blueee', $array);
echo ($i !== false) ? $i : -1; // -1 i.e. not found
?>
