How to return data from PHP function?

PHP functions can return data in the following ways: Use return statements to implicit type conversion to return arrays and to return an object

How to return data from PHP functions

PHP functions can return data, allowing us to access the results of function calculations when the function is called. Here are several ways to return data:

1. Use the return statement

The most direct way is to use return statement, which immediately stops function execution and returns the specified value. For example:

function get_name() {
  return "Jack";
}

$name = get_name(); // $name 将被赋值为 "Jack"

2. Implicit type conversion

If the function does not contain an explicit return statement, PHP will implicitly return the function's The value of the last expression. For example:

function calculate_average($nums) {
  $sum = 0;
  foreach ($nums as $num) {
    $sum += $num;
  }
  return $sum / count($nums);
}

$avg = calculate_average([1, 2, 3, 4, 5]); // $avg 将被赋值为 3

3. Return array

The function can also return an array, allowing you to return multiple values. To return an array, simply assign the array to a variable and use return to return the variable. For example:

function get_user_info($id) {
  return [
    "name" => "Alice",
    "email" => "alice@example.com",
    "age" => 25
  ];
}

$user_info = get_user_info(1); // $user_info 将包含包含用户信息的数组

4. Return an object

If you want to return an object, you can use the new operator to create a new object instance and return it. For example:

class Person {
  public $name;
  public $age;

  public function __construct($name, $age) {
    $this->name = $name;
    $this->age = $age;
  }
}

function create_person($name, $age) {
  return new Person($name, $age);
}

$person = create_person("Bob", 30); // $person 将包含一个 Person 对象

Practical example:

Consider a function that returns user details:

function get_user_details($user_id) {
  $query = "SELECT * FROM users WHERE id = ?";
  $result = execute_query($query, [$user_id]);
  return $result[0]; // 假设 execute_query() 返回一个结果数组
}

$user_info = get_user_details(1); // 获取用户 1 的详细信息

In this example, get_user_details( ) Use a query to get a single user row and return the row as an array.

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