php判断一维数组中相同元素出现的次数

php中统计一维数组相同元素出现的的次数，可以用php自带的函数array_count_values，用法示例如下：

$a =array("A","Cat","Dog","A","Dog");
$a = array_count_values($a);
print_r($a);

运行输出打印结果如下：

Array
(
    [A] => 2
    [Cat] => 1
    [Dog] => 2
)

当然如果你不想使用PHP自带的函数，也可以自己实现，实例如下：

function arr_count_v($arr){
    $newArr = array();
    foreach ($arr as $k => $v) {
        if(empty($newArr[$v])){
            $newArr[$v] = 1;
        }else{
            $newArr[$v] ++;
        }
    }
    return $newArr;
}

$a =array("A","Cat","Dog","A","Dog");
$a = array_count_v($a);
print_r($a);

打印结果：

Array
(
    [A] => 2
    [Cat] => 1
    [Dog] => 2
)