Public functions vs Functions in CodeIgniter

问题:

In PHP, What is the difference between declaring methods inside class like

public function VS function

For example:

public function contact()
{
    $data['header'] = "Contact";
    $this->load->view('admin/admin_contact', $data);
}

VS

function contact()
{
    $data['header'] = "Contact";
    $this->load->view('admin/admin_contact', $data);
}

Is it better practice to use public function or function and why?

回答1:

Methods declared with any explicit visibility keyword is best practice. It looks and feels better and it doesn't confuse people.

• Most PHP5 coding conventions (e.g. Zend, Symfony...) require the public keyword, so it's familiar.
• It means that variable and method declarations use the same syntax.
• It's more explicit and forces developers to consider their method visibility.

回答2:

According to PHP.net

Class methods may be defined as public, private, or protected. Methods declared without any explicit visibility keyword are defined as public.

for best practice, i suggest using visibility keywords (esp when using higher versions of PHP). it prevents confusion (like the one you are in now) and promotes standard practice in coding.

回答3:

There is no difference between these two. Both are the same. In codeigniter both have same meaning and can be called by using standard URI tags unless you give a '_' in front of your function name _fname() will not be called

回答4:

They are the same thing .... if you do not specify the visibility methods / functions are declared as public

Methods declared without any explicit visibility keyword are defined as public

from the docs here

回答5:

If you really want best practice you will always use public. But for the codeigniter Framework it doesn't mather if you declare it public or not. Note that if you want a controller to be private you dont use private but you will use the underscore (_) in front of your controller name so it wont be visible.

回答6:

• Both declarations are same and both functions will be available by URI request in codeigniter
• To prevent a method from being called by user use private or protected access specifiers.