Getting the array length method in PHP is simple, PHP provides us with two functions to calculate the length of one-dimensional array, such as count,sizeof can be directly statistical array length Oh, let's look at a few examples.
How PHP Gets the length of the array, using the PHP function count (), or sizeof ()
For example:
Copy CodeThe code is as follows:
$arr = Array (' 0 ', ' 1 ', ' 2 ', ' 3 ', ' 4 ');
echo count ($arr);
Output 5
$arr = Array (' A ', ' B ', ' C ');
echo sizeof ($arr);
Output 3
sizeof () and count () have the same purpose, both of which can return the number of array elements. You can get the number of elements in a regular scalar variable, if the array passed to the function is an empty array, or is an array of variables that are not set, the number of elements returned is 0;
Like the function of two functions, the manual says that sizeof () is the alias of the function count ().
so how to count the length of multidimensional arrays? Continue to see examples
For example, the array you are reading is a two-dimensional array:
Copy CodeThe code is as follows:
$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 $arr is not a news message, it is necessary to write:
Copy CodeThe code is as follows:
if (Is_array ($arr) && count ($arr, count_normal) >0)
{
.....
} else {
.....
}
?>
You can use this code to test the function:
Copy CodeThe code is as follows:
$arr =array (
0=>array (' title ' = ' News 1 ', ' viewnum ' = ' 123 ', ' content ' = ' ZAQXSWEDCRFV '),
1=>array (' title ' = ' News 2 ', ' viewnum ' = ' content ' = ' qwertyuiopzxcvbnm ')
);
Echo ' does not count multidimensional arrays: '. Count ($arr, 0);//count ($arr, Count_normal)
echo "
";
Echo ' statistics multidimensional array: '. Count ($arr, 1);//count ($arr, count_recursive)
?>
