Introduction to the method of counting the number of elements in multi-dimensional arrays in PHP (with code)

This article brings you an introduction to the method of counting the number of multi-dimensional array elements in PHP (with code). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

Under normal circumstances, you can use count to directly count the number of elements in the array

$arr = [
'a',
'b',
];
echo count($arr);//2

But when encountering a two-digit array, we want to count the number of elements in the second level. At this time, you can use the second parameter of the count function,
count($arr, $mode = 0);$mode(0: Count all elements in one dimension, 1: Loop count and traverse elements)
In $ When mode=1, the count function will count the number of elements in a loop. If element $a is an array, the total number will be increased by the number of elements in $a plus 1;

$arr = [
'a' => 'b',
'c' => [
    'd',
],
];
echo count($arr, 1);//3('b',['d'],'d')

As long as the two-dimensional array has According to the rules, you can easily count the number of two-dimensional elements

$arr = [
'a' => [
    'd',
    'e',
],
'c' => [
    'd',
    'g',
],
];
echo count($arr, 1) - count($arr);//4

You can also use array_map

$arrCount = 0;
$countFun = function($a) use(&$arrCount) {
$arrCount += count($a);
return $arrCount;
};
array_map($countFun,$arr);
echo $arrCount;

Remember $arrCount must be passed by reference
If you want to count the number of elements of a three-dimensional array

$arr = [
'a' => [
   'b' => [
       'd',
       'e',
       'g',
   ],
],
'c' => [
    'd' => [
        'd',
        'g',
    ],
],
];
$arrCount = 0;
$countFun = function($a) use(&$arrCount) {

$arrCount += count($a, 1) - count($a);
return $arrCount;
};
array_map($countFun,$arr);
echo $arrCount;

If you want to count the number of elements of a four-dimensional array

$arr = [
'a' => [
   'b' => [
       'd' => [
           'e',
           'g',
       ],
   ],
],
'c' => [
    'd' => [
        'd' => [
            'e',
            'g',
            'f'
        ],
    ],
],
];
$arrCount = 0;
$napFun = function($a) use(&$arrCount) {

$countFun = function($a) use(&$arrCount) {
    $arrCount += count($a, 1) - count($a);
    return $arrCount;
};
array_map($countFun,$a);
return $arrCount;
};
array_map($napFun,$arr);
echo $arrCount;

It is recommended to use if you want to count three dimensions or higher. Recursive method

$arr = [
'a' => [
    'b' => [
       'd' => [
           'e',
           'g',
       ],
    ],
],
'c' => [
    'd' => [
        'd' => [
            'e',
            'g',
            'f'
        ],
    ],
],
];

function arrCount($arr, &$arrCount, $level){
if(0 === $level){
    $arrCount += count($arr);
    print_r($arr);
}else{
    $level--;
    foreach($arr as $a){
        arrCount($a, $arrCount, $level);
    }
}
}
$count = 0;
$level = 3;
arrCount($arr,$count,$level);
echo $count;

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