如何检查
$something['say']'bla''omg'$something = array('say' => 'bla', 'say' => 'omg');
您可以使用 PHP in_array 函数：
if(in_array("bla", $yourarray))
{
echo "has bla";
}
使用说明
ifif(isset($something['say']) && $something['say'] === 'bla') {
// do something
}
顺便说一句，您使用键
say使用：
in_array()$search_array = array('user_from', 'lucky_draw_id', 'prize_id');
if (in_array('prize_id', $search_array)) {
echo "The 'prize_id' element is in the array";
}
这是输出：
The 'prize_id' element is in the array使用：
array_key_exists()$search_array = array('user_from', 'lucky_draw_id', 'prize_id');
if (array_key_exists('prize_id', $search_array)) {
echo "The 'prize_id' element is in the array";
}
无输出
总之，
array_key_exists()in_array()以下是更多示例：
<?php
/**++++++++++++++++++++++++++++++++++++++++++++++
* 1. Example with an associative array using in_array
*
* IMPORTANT NOTE: in_array is case-sensitive
* in_array — Checks if a value exists in an array
*
* DOES NOT WORK FOR MULTI-DIMENSIONAL ARRAY
*++++++++++++++++++++++++++++++++++++++++++++++
*/
$something = array('a' => 'bla', 'b' => 'omg');
if (in_array('omg', $something)) {
echo "|1| The 'omg' value found in the associative array ||";
}
/**++++++++++++++++++++++++++++++++++++++++++++++
* 2. Example with an index array using in_array
*
* IMPORTANT NOTE: in_array is case-sensitive
* in_array — Checks if a value exists in an array
*
* DOES NOT WORK FOR A MULTI-DIMENSIONAL ARRAY
*++++++++++++++++++++++++++++++++++++++++++++++
*/
$something = array('bla', 'omg');
if (in_array('omg', $something)) {
echo "|2| The 'omg' value found in the index array ||";
}
/**++++++++++++++++++++++++++++++++++++++++++++++
* 3. trying with array_search
*
* array_search — Searches the array for a given value
* and returns the corresponding key if successful
*
* DOES NOT WORK FOR MULTI-DIMENSIONAL ARRAY
*++++++++++++++++++++++++++++++++++++++++++++++
*/
$something = array('a' => 'bla', 'b' => 'omg');
if (array_search('bla', $something)) {
echo "|3| The 'bla' value found in the assoc array ||";
}
/**++++++++++++++++++++++++++++++++++++++++++++++
* 4. trying with isset (fastest ever)
*
* isset — Determine if a variable is set and
* is not NULL
*++++++++++++++++++++++++++++++++++++++++++++++
*/
$something = array('a' => 'bla', 'b' => 'omg');
if($something['a']=='bla'){
echo "|4| Yeah!! 'bla' found in array ||";
}
/**
* OUTPUT:
* |1| The 'omg' element value found in the assoc array ||
* |2| The 'omg' element value found in the index array ||
* |3| The 'bla' element value found in the assoc array ||
* |4| Yeah!! 'bla' found in array ||
*/
?>
这里是 PHP 演示。
您可以使用：
array_search()in_array()array_flip()array_key_exists()in_array() 没问题，但如果您需要检查值是否存在并返回关联的键，则 array_search 是更好的选择。
$data = [
'hello',
'world'
];
$key = array_search('world', $data);
if ($key) {
echo 'Key is ' . $key;
} else {
echo 'Key not found';
}
这将打印“Key is 1”。
检查索引是否已定义：
isset($something['say'])您可以使用 isset() 测试数组是否具有某个元素，有时甚至更好 array_key_exists() （文档解释了差异）。如果您无法确定数组中是否有一个索引为“say”的元素，您应该首先测试它，否则您可能会收到“警告：未定义的索引...”消息。
至于测试元素的值是否等于字符串，您可以使用 == 或（有时更好）身份运算符 === ，它不允许 类型杂耍。
if( isset($something['say']) && 'bla'===$something['say'] ) {
// ...
}
只需使用PHP函数
array_key_exists()<?php
$search_array = array('first' => 1, 'second' => 4);
if (array_key_exists('first', $search_array)) {
echo "The 'first' element is in the array";
}
?>
<?php
if (in_array('your_variable', $Your_array)) {
$redImg = 'true code here';
} else {
$redImg = 'false code here';
}
?>
bool in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] )
in_array的另一种用途 in_array() 以数组为针
<?php
$a = array(array('p', 'h'), array('p', 'r'), 'o');
if (in_array(array('p', 'h'), $a)) {
echo "'ph' was found\n";
}
if (in_array(array('f', 'i'), $a)) {
echo "'fi' was found\n";
}
if (in_array('o', $a)) {
echo "'o' was found\n";
}
?>
假设您使用的是简单数组，即
$MyArray = array("red","blue","green");
您可以使用此功能
function val_in_arr($val,$arr){
foreach($arr as $arr_val){
if($arr_val == $val){
return true;
}
}
return false;
}
用途：
val_in_arr("red",$MyArray); //returns true
val_in_arr("brown",$MyArray); //returns false
关联数组只能定义一次键，因此该数组永远不会存在。否则，只需使用
in_array()