Array is the most commonly used type, so how to calculate the number of a one-dimensional array. In fact, we can use one of the mathematical functions we learned before: count().
Let’s take a look at the usage of the count function:
int count (mixed $ variable)
Note:
1. The parameter $ variable is required to be an array or an object that can be counted
Then we can try to use the statistical function to count the number of arrays.
<?php $a[0] = 1; $a[1] = 3; $a[2] = 5; $result = count($a); // $result == 3 $b[0] = '迪奥和奥迪我都爱'; $b[5] = '努力开创未来'; $b[10] = '为了未来而努力'; $result = count($b); $data = [ 'baidu' =>'百度', 'ali' => '阿里', 'tencent' => '腾讯', ]; echo count($data); $erwei = [ [ 'baidu' =>'百度', 'ali' => '阿里', 'tencent' => '腾讯', ], [ 'netease' =>'网易', 'sohu' => '搜狐', 'sina' => '新浪', ] ]; //试试输出一个二维数组个数 echo count($erwei); //试试输出二维数组中某个元素的个数 echo count($erwei[1]); ?>
Through the above example, we found that both the index array and the number of associative arrays can be output.
If it is a two-dimensional array, this function will only count the number of array elements in the current dimension. As in the above example: $erwei.
So the result of count($erwei) is 2. When counting($erwei[1]), the result is 3.