Data analysis function of PHP function

PHP is a high-performance, open source scripting language widely used in web development. With the development of data analysis technology, more and more data need to be processed and analyzed. PHP provides some data analysis functions that can be used to process various types of data. This article will introduce how to use PHP data analysis functions and examples.

1. Statistical function

1. count() function: Returns the number of elements in the array.

Example:

$numbers = array(1, 2, 3, 4, 5);
echo count($numbers); // 输出 5

2. array_sum() function: Calculates the sum of all values ​​in an array.

Example:

$numbers = array(1, 2, 3, 4, 5);
echo array_sum($numbers); // 输出 15

3. array_average() function: Calculate the average of all values ​​in the array.

Example:

$numbers = array(1, 2, 3, 4, 5);
echo array_sum($numbers) / count($numbers); // 输出 3

2. Sorting function

1. sort() function: Arrange the array in ascending order.

Example:

$numbers = array(5, 4, 3, 2, 1);
sort($numbers);
print_r($numbers); // 输出Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 )

2. rsort() function: Sort the array in descending order.

Example:

$numbers = array(1, 2, 3, 4, 5);
rsort($numbers);
print_r($numbers); // 输出Array ( [0] => 5 [1] => 4 [2] => 3 [3] => 2 [4] => 1 )

3. Filter function

1. array_filter() function: Filter the array and only retain elements that meet the conditions.

Example 1:

$numbers = array(1, 2, 3, 4, 5);
$new_numbers = array_filter($numbers, function($value) {
    return $value % 2 == 0; // 只保留偶数
});
print_r($new_numbers); // 输出Array ( [1] => 2 [3] => 4 )

Example 2:

$employees = array(
    array('name' => '张三', 'age' => 25, 'gender' => '男'),
    array('name' => '李四', 'age' => 30, 'gender' => '女'),
    array('name' => '王五', 'age' => 35, 'gender' => '男')
);
$new_employees = array_filter($employees, function($employee) {
    return $employee['gender'] == '男'; // 只保留男员工
});
print_r($new_employees); // 输出Array ( [0] => Array ( [name] => 张三 [age] => 25 [gender] => 男 ) [2] => Array ( [name] => 王五 [age] => 35 [gender] => 男 ) )

2. array_unique() function: Remove duplicate elements from the array.

Example:

$numbers = array(1, 2, 1, 3, 2, 4, 5);
$new_numbers = array_unique($numbers);
print_r($new_numbers); // 输出Array ( [0] => 1 [1] => 2 [3] => 3 [5] => 4 [6] => 5 )

4. String function

1. strlen() function: Get the length of the string.

Example:

$string = 'Hello world';
echo strlen($string); // 输出 11

2. strpos() function: Find the first occurrence of a string.

Example:

$string = 'Hello world';
echo strpos($string, 'o'); // 输出 4

3. substr() function: intercept a substring of specified length from a string.

Example:

$string = 'Hello world';
echo substr($string, 6, 5); // 输出 world

The above are some common examples of PHP data analysis functions. Through them, we can implement functions such as array statistics, sorting, filtering, and string operations. In actual projects, these functions can be combined for comprehensive analysis and processing according to different needs to improve the utilization value of data.

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