adding default parameters of the function as result of other function - php

Question

Hi I have question it is possible to adding default parameters of the function as result of other function? For example:
static function addParameter(){
return rand(10,100)
}
function doSomething($year=$this->addParameter()) or
function doSomething($year=class::addParameter())
I need to pass actual year and month to my function. When i pass
function($month=3, $year=2016)
it work then but i not want to write this from hand but want to use function or something to always return actual month and year.

Answer 1

Short answer: no, you can't.
http://php.net/manual/en/functions.arguments.php states that:
The default value must be a constant expression, not (for example) a variable, a class member or a function call.
You can use default null value (if normally function does not take one) and check if parameter is null, then get value from function:
function testfun($testparam = null) {
if ($testparam == null) $testparam = myclass::funToReturnParam();
// Rest of function body
}

Answer 2

Yo can implement it like this
<?php
class Core {
static function addParameter(){
return rand(10,100);
}
}
$core = new Core();
function doSomething($rand){
echo 'this is rand '.$rand;
}
doSomething(Core::addParameter());
You can change the function defination according to your requirement.
hope it helps :)

Answer 3

From the PHP Manual (emphasis mine):
The default value must be a constant expression, not (for example) a variable, a class member or a function call.
So only scalar types(boolean, int, string etc), arrays and null are allowed.
A workaround could be to check if the parameter is null and set it within the function:
function doSomething($year = null) {
if (!$year) {
$year = addParameter();
}
//actually do something
}