Something wrong when set public class

PHP
1

I have two classes as below:

product.php


<?php
	class Product {
		private $id;
		private $name;
		private $price;
		private $lastUpdate;
		private $category;
		
		//public function Product($id) {
		//	$this->id = $id;
		//}
		
		public function Product($id, $name, $price, $lastUpdate) {
			$this->id = $id;
			$this->name = $name;
			$this->price = $price;
			$this->lastUpdate = $lastUpdate;
		}
		
		public function getId() {
			return $this->id;
		}
		
		public function setId($id) {
			$this->id = $id;
		}
		
		public function getName() {
			return $this->name;
		}
		
		public function setName($name) {
			$this->name = $name;
		}
		
		public function getPrice() {
			return $this->price;
		}
		
		public function setPrice($price) {
			$this->price = $price;
		}
		
		public function getLastUpdate() {
			return $this->lastUpdate;
		}
		
		public function setLastUpdate($lastUpdate) {
			$this->lastUpdate = $lastUpdate;
		}
		
		public function getCategory() {
			return $this->category;
		}
		
		public function setCategory($category) {
			$this->category = $category;
		}
	}
?>

index.php


<?php
	include('product.php');
	include('ShoppingCartItem.php');
	//include('ShoppingCart.php');
	
	$product = new Product(1, 'Note book', 25000, '25/1/2013');
	//echo $product->getId();
	$scItem = new ShoppingCartItem($product);
	
	//echo $scItem->getQuantity();
?>

When I put “public” for class Product, error occur and if I remove it, no error:


<?php
	public class Product {
		//
	}
?>

Parse error: syntax error, unexpected T_PUBLIC in C:\xampp\htdocs\demo\passing_object_to_function\product.php on line 2

Why don’t I do this? And why don’t I add a construct function “Product” with one parameter “$id”?

2

[quote=“greedyman”]

When I put “public” for class Product, error occur and if I remove it, no error:


<?php
	public class Product {
		//
	}
?>

You cannot add “public” to class definitions in PHP, only to methods.

I don’t really understand your question…

3

As Lemon Juice said, classes are by definition public and cannot be stated otherwise. Remove the public keyword and it will fix the issue.

However, it should be noted that __construct() is preferred to using the class’ name as the constructor. See: http://php.net/manual/en/language.oop5.decon.php

4

[quote=“Lemon_Juice,post:2,topic:26287”]

Thanks! I see.
@Lemon Juice: Do you see a paragraph I marked by orange color in Product class? As Java or C#, I can make a lot of construct function with one, two, …etc parameter(s) but in PHP, I can’t. When I try to do this, I see an error:

Fatal error: Cannot redeclare Product::Product() in C:\xampp\htdocs\demo\passing_object_to_function\product.php on line 13

This is thing I don’t understand?

5

I see, you mean method overloading. It’s not possible in PHP, the closest you can get to it is accept optional parameters and then use if statements to do different things:


public function Product($id, $name = null, $price = null, $lastUpdate = null) {
  if ($name === null && $price === null && $lastUpdate === null) {
    // do something when only $id is given...
  } else {
    // do something else...
  }
}
6

That means that your method exists.

About overloading, you may use __call but not for the constructor


<?php

class test {

	function some1($a) {
		echo '1 => '.$a;
	}
	
	function some2($a, $b) {
		echo '2 => '.$a.', '.$b;
	}
	
	public function __call($method, $params) {
		if(count($params) == 2) {
			$this->some2($params[0], $params[1]);
		} elseif(count($params) == 1) {
			$this->some1($params[0]);
		}
	}

}

$a = 'a';
$b = 'b';
$test = new test;
$test->some($a);
echo '<br />----<br />';
$test->some($a, $b);
?>
7

actually you can use func_get_args() and manually code the branching, but it’s a bit hacky and makes it very difficult for people using the class to see what is needed by the constructor:



class Test {
	public function __construct() {
		print_r(func_get_args());
	}
}

new Test(1, 2);
new Test('A', 'B', 'C');
8

I just repaired it. Thanks you!