PHP determines how many data types an array has

PHP is a programming language widely used in the field of Web development. It provides a rich function library and language features, including array operations and other functions. In PHP, multiple methods can be used to determine how many data types an array has.

1. Use the count function

The count function is a built-in function in PHP. Using this function in an array can be used to get the number of elements in the array, and then determine how many elements the array has. type of data. The following is a simple code example:

<?php  
$array = array(1,2,'hello',3.14,true,array('a','b','c'));  
$length = count($array);  
echo '数组中元素的个数为：'.$length.',类型个数为：'.count(array_unique(array_map('gettype',$array)));  
?>

In the above code, we define an array containing multiple data types, use the count function in PHP to obtain the number of array elements, and use the array_map function to obtain the number of elements in the array For the data type of each element, use the array_unique function to remove duplicate element types, and finally get the total number of data types in the array.

2. Use foreach loop

In addition to the count function, we can also use the foreach loop to traverse each element in the array and count the number of different data types in the array. It is very simple to implement. You can see the following code:

<?php  
$array = array(1,2,'hello',3.14,true,array('a','b','c'));  
$result = array();  
foreach($array as $value){  
    $value_type = gettype($value);  
    if(!isset($result[$value_type])){  
        $result[$value_type] = 1;  
    }else{  
        $result[$value_type] += 1;  
    }  
}  
echo '数组中元素的个数为：'.count($array).',数据类型的个数为：'.count($result);  
?>

In the above code, we define an array $result to record the type of each element and the number of occurrences during the traversal process, by traversing and counting the different data in the array The number of types ultimately results in the total number of different data types in the array.

3. Use the array_column function

In addition to the previous two methods, we can also use the array_column function to count the number of different data types in the array. The following is a code example:

<?php  
$array = array(1,2,'hello',3.14,true,array('a','b','c'));  
$type_array = array_map(function($value){ return gettype($value); }, $array);  
$result = count(array_unique(array_column(array_combine($type_array, $type_array), 0)));  
echo '数组中元素的个数为：'.count($array).',数据类型的个数为：'.$result;  
?>

In the above code, we use the array_combine and array_column functions to convert the array into a two-dimensional array similar to key-value pairs. In this array, the subscript represents the element type. , the corresponding value represents the number of times this type appears in the array, and finally counting the number of key-value pairs present in it, the total number of different data types in the array can be obtained.

Summary

In this article, we introduced three methods to determine the number of different data types in an array. These methods are commonly used when operating arrays, and are often used in operations such as filtering and statistics. In actual use, developers can choose different methods according to actual needs to achieve better results.

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