PHP :: colon used?

[robin01]

Hello Everybody,

I’m not even sure how to search for the answer to the question but what does the colon mean and how is it used ::

example: $test::test

[vectorialpx]

the double-colon sign is used for a static call.

<?php

class test
{
    const george = 'G';
    public static function getName()
    {
        return 'Mike!';
    }
}

// we can have
$testObj = new test;
echo $testObj::george.'<br>';
echo $testObj::getName().'<br>';
// or, same thing
echo test::george.'<br>';
echo test::getName().'<br>';

[robin01]

Hi Vectorialpx,

thanks for the reply back.
I seen example where an arrow is used to point to an objects example $testObj->george, how is this different?

question 2,
you have test::george, is this mean that you dont have to create an object?

[vectorialpx]

Your second question answers the first
I hope the next code will answer better

<?php

class human
{
    // by convention, constants will be uppercase
    // constants cannot be changed
    const FIRST_NAME = 'G';
// ---
    // this is a static property of the object
    // properties (are like variables) can be changed
    // moreover, static properties will remain and can be used globally
    // human::$name will be available everywhere
    // and once is set, will remain there
    // (in one call, do not confuse it with sessions)
    public static $name = 'Maria';
// ---
    // this is a simple property of the object
    protected $gender = 'female';
// ---
    // static variables can be changed and
    public static function setName($n)
    {
        self::$name = $n;
    }
// ---
    // get full name of the 
    public static function getFullName()
    {
        // invalid code:
        // return $this->gender;
        // because we may not have an instance of the object
//
        // valid code
        return self::FIRST_NAME.' '.self::$name;
    }
// ---
    public function getFullDetails()
    {
        return [
            // you can use static calls into your methods
            'name' => self::getFullName(),
            'gender' => $this->gender,
        ];
    }
}

$hClass = new human;
$hClass::setName('Mark');
var_dump(human::getFullName());
var_dump($hClass->getFullDetails());