这是函数-

public function is_assoc_array($array){

    if(is_array($array) !== true){
        return false;
    }else{

        $check = json_decode(json_encode($array));

        if(is_object($check) === true){
            return true;
        }else{
            return false;
        }

    }

}

一些例子

    print_r((is_assoc_array(['one','two','three']))===true?'Yes':'No'); \\No
    print_r(is_assoc_array(['one'=>'one','two'=>'two','three'=>'three'])?'Yes':'No'); \\Yes
    print_r(is_assoc_array(['1'=>'one','2'=>'two','3'=>'three'])?'Yes':'No'); \\Yes
    print_r(is_assoc_array(['0'=>'one','1'=>'two','2'=>'three'])?'Yes':'No'); \\No

在其中一个答案中@devios1有一个类似的解决方案，但这只是使用PHP的内置json相关函数的另一种方式。我还没有检查这个解决方案在性能方面如何与其他已经在这里发布的解决方案相比。但它确实帮助我解决了这个问题。希望这能有所帮助。

我认为标量数组的定义因应用程序而异。也就是说，一些应用程序将需要更严格的定义标量数组，而一些应用程序将需要更宽松的定义。

下面我将介绍3种不同严格程度的方法。

<?php
/**
 * Since PHP stores all arrays as associative internally, there is no proper
 * definition of a scalar array.
 * 
 * As such, developers are likely to have varying definitions of scalar array,
 * based on their application needs.
 * 
 * In this file, I present 3 increasingly strict methods of determining if an
 * array is scalar.
 * 
 * @author David Farrell <DavidPFarrell@gmail.com>
 */

/**
 * isArrayWithOnlyIntKeys defines a scalar array as containing
 * only integer keys.
 * 
 * If you are explicitly setting integer keys on an array, you
 * may need this function to determine scalar-ness.
 * 
 * @param array $a
 * @return boolean
 */ 
function isArrayWithOnlyIntKeys(array $a)
{
    if (!is_array($a))
        return false;
    foreach ($a as $k => $v)
        if (!is_int($k))
            return false;
    return true;
}

/**
 * isArrayWithOnlyAscendingIntKeys defines a scalar array as
 * containing only integer keys in ascending (but not necessarily
 * sequential) order.
 * 
 * If you are performing pushes, pops, and unsets on your array,
 * you may need this function to determine scalar-ness.
 * 
 * @param array $a
 * @return boolean
 */ 
function isArrayWithOnlyAscendingIntKeys(array $a)
{
    if (!is_array($a))
        return false;
    $prev = null;
    foreach ($a as $k => $v)
    {
        if (!is_int($k) || (null !== $prev && $k <= $prev))
            return false;
        $prev = $k;
    }
    return true;
}

/**
 * isArrayWithOnlyZeroBasedSequentialIntKeys defines a scalar array
 * as containing only integer keys in sequential, ascending order,
 * starting from 0.
 * 
 * If you are only performing operations on your array that are
 * guaranteed to either maintain consistent key values, or that
 * re-base the keys for consistency, then you can use this function.
 * 
 * @param array $a
 * @return boolean
 */
function isArrayWithOnlyZeroBasedSequentialIntKeys(array $a)
{
    if (!is_array($a))
        return false;
    $i = 0;
    foreach ($a as $k => $v)
        if ($i++ !== $k)
            return false;
    return true;
}

function checkAssoc($array){
    return  ctype_digit( implode('', array_keys($array) ) );
}

有时你可以只检查第一个数组的Key是否为0。

$isSequential = array_keys($arr)[0] ===

，或更快，但更冗长的版本:

重置(arr);$isSequential = key($arr) === 0

除非PHP有这样的内置功能，否则您无法在小于O(n)的时间内完成—枚举所有键并检查整数类型。事实上，你还想确保没有漏洞，所以你的算法可能是这样的:

for i in 0 to len(your_array):
    if not defined(your-array[i]):
        # this is not an array array, it's an associative array :)

但为什么要麻烦呢?只需假设数组是您所期望的类型。如果不是，它就会在你面前爆炸——这就是动态编程!测试你的代码，一切都会很好……

一种廉价而肮脏的方法是这样检查:

isset($myArray[count($myArray) - 1])

.．.如果你的数组是这样的，你可能会得到一个假阳性:

$myArray = array("1" => "apple", "b" => "banana");

一个更彻底的方法可能是检查钥匙:

function arrayIsAssociative($myArray) {
    foreach (array_keys($myArray) as $ind => $key) {
        if (!is_numeric($key) || (isset($myArray[$ind + 1]) && $myArray[$ind + 1] != $key + 1)) {
            return true;
        }
    }
    return false;
}
// this will only return true if all the keys are numeric AND sequential, which
// is what you get when you define an array like this:
// array("a", "b", "c", "d", "e");

or

function arrayIsAssociative($myArray) {
    $l = count($myArray);
    for ($i = 0; $i < $l, ++$i) {
        if (!isset($myArray[$i])) return true;
    }
    return false;
}
// this will return a false positive on an array like this:
$x = array(1 => "b", 0 => "a", 2 => "c", 4 => "e", 3 => "d");