PHP count Multidimensional Array length statistics implementation method _php tutorial

Count multidimensional Array length statistics implementation method in PHP there are a few friends you can refer to below.

The following program runs the result as ()

The code is as follows	Copy Code
? $numb =array ( Array (10,15,30), Array (10,15,30), Array (10,15,30) ); echo Count ($numb, 1); A.3 b.12 C.6 D.9

Answer: B

If mode is set to Count_recursive (or 1) in the COUNT function, the number of elements of the array in the multidimensional array is recursively computed (that is, 12 of your results). If you do not set mode defaults to 0. multidimensional arrays (arrays in arrays) are not instrumented (Result 3).

The first traversal is an array of outer arrays to derive two elements ("Color1″," Color2″, "Color3″") to 3
The iterated ("Color1″," Color2″, "Color3″") array is derived from 9 elements of 9
The result is 3+9=12.

Reference

The code is as follows	Copy Code
$fruits = Array ( Array (1, 2,null,null, 5, 6), Array (1, 2,null,null, 5, 6), ); Echo (count ($fruits [0])); ?>

You might be talking about arrays that are defined in other ways, such as direct use:

The code is as follows	Copy Code
$fruits [0][0]=1; $fruits [0][3]=1; $fruits [0][4]=1; Echo (count ($fruits [0])); ?>

This will output 3, because the array in PHP does not require the index to be contiguous, the reference manual has the following paragraph:

Array
The array in PHP is actually an ordered graph. A graph is a type that maps values to keys. This type is optimized in many ways, so you can use it as a real array, or list (vector), hash list (an implementation of the graph), dictionaries, collections, stacks, queues, and more possibilities. Because you can use another PHP array as a value, you can also easily emulate a tree.

Instance

Obtaining the length of the first dimension of a two-dimensional or multidimensional array is a common procedure to judge, such as the array you are reading is a two-dimensional array:

The code is as follows	Copy Code
$arr =array ( 0=>array (' title ' = ' News 1 ', ' viewnum ' = ' 123 ', ' content ' = ' ZAQXSWEDCRFV '), 1=>array (' title ' = ' News 2 ', ' viewnum ' = ' content ' = ' qwertyuiopzxcvbnm ') ); ?>

If you want to count the length of the array $arr, which means that the two-dimensional array has only two news, you want the number is also 2, but if you use the Count ($arr) different versions of PHP, the results of the statistics are not the same;
Later found in the PHP manual, the Count function has a second parameter, which is explained as follows:
The Count function has two parameters:
0 (or Count_normal) is the default and does not detect multidimensional arrays (arrays in arrays);
1 (or count_recursive) for detecting multidimensional arrays,
So if you want to judge the reading of the array $arr is not a news message, it is necessary to write:

The code is as follows	Copy Code
if (Is_array ($arr) && count ($arr, count_normal) >0) { ..... } else { ..... } ?>

You can use this code to test the function:

The code is as follows	Copy Code
$arr =array ( 0=>array (' title ' = ' News 1 ', ' viewnum ' = ' 123 ', ' content ' = ' ZAQXSWEDCRFV '), 1=>array (' title ' = ' News 2 ', ' viewnum ' = ' content ' = ' qwertyuiopzxcvbnm ') ); Echo ' does not count multidimensional arrays: '. Count ($arr, 0);//count ($arr, Count_normal) echo " "; Echo ' statistics multidimensional array: '. Count ($arr, 1);//count ($arr, count_recursive) ?>

Well, at this point, we've solved the problem of getting the first-dimensional length of a two-dimensional or multidimensional array in PHP

http://www.bkjia.com/PHPjc/631599.html www.bkjia.com true http://www.bkjia.com/PHPjc/631599.html techarticle count Multidimensional Array length statistics implementation method in PHP there are a few friends you can refer to below. The following program runs as follows () code copy code below? $numb =array (Array (10,15,30), AR ...

