创建一个people类，包含id、name、age;。 创建一个 student 类，继承people类，包含 school、gradetclass、sno，一个function(输出所有信息);PHP

以下是 PHP 代码实现：

<?php
class People {
  public $id;
  public $name;
  public $age;

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

class Student extends People {
  public $school;
  public $grade_class;
  public $sno;

  function __construct($id, $name, $age, $school, $grade_class, $sno) {
    parent::__construct($id, $name, $age);
    $this->school = $school;
    $this->grade_class = $grade_class;
    $this->sno = $sno;
  }

  function display_info() {
    echo "ID: " . $this->id . "<br>";
    echo "Name: " . $this->name . "<br>";
    echo "Age: " . $this->age . "<br>";
    echo "School: " . $this->school . "<br>";
    echo "Grade and Class: " . $this->grade_class . "<br>";
    echo "Student Number: " . $this->sno . "<br>";
  }
}

$student = new Student(1, "Alice", 18, "ABC High School", "Grade 12, Class 1", "001");
$student->display_info();
?>

运行以上代码，输出结果为：

ID: 1
Name: Alice
Age: 18
School: ABC High School
Grade and Class: Grade 12, Class 1
Student Number: 001