how can i get value from inside of function? - php

Question

Is it possible to get those values inside of function and use those outside of function
here is my code:
<?
function expenditure () {
$totalexpenditure = $sum1 + $sum2;
}
function income () {
totalincome = $sum1 + $sum2;
}
$profit = $totalincome - $totalexpenditure;
?>
now my question is how can i get value of totalincome and toatalexpenditure ?
i am learning php alos new in php so please help me guys.

Answer 1

<?
function expenditure ($sum1, $sum2) {
$totalexpenditure = $sum1 + $sum2;
return $totalexpenditure;
}
function income ($sum1, $sum2) {
$totalincome = $sum1 + $sum2;
return $totalincome;
}
$profit = income ($sum1, $sum2) - expenditure($sum1, $sum2) ;
?>
return statement

Answer 2

Your code is wrong, because:
the variables within functions do not have value assigned (you should assign it preferably by function parameters, but another - working, but wrong - solution is making them global variables),
in the example given, $profit will be always 0 (zero).
The solutions are three:
Solution no. 1:
function expenditure ($sum1, $sum2) {
$expenditure = $sum1 + $sum2;
return $expenditure;
}
function income ($sum1, $sum2) {
$income = $sum1 + $sum2;
return $income;
}
And then you can use it like that:
$profit = income(10, 200) - expenditure(20,18);
Solution no. 2:
class Finances {
public $expenditure = 0;
public $income = 0;
public function addExpense($expense) {
$this->expenditure = $this->expenditure + $expense;
return $this;
}
public function addIncome($income) {
$this->income = $this->income + $income;
return $this;
}
public function getProfit() {
return $this->income - $this->expenditure;
}
}
and then you can use it like that:
$my_finances = new Finances();
$my_finances->addExpense(20)->addExpense(18)->addIncome(10)->addIncome(10);
$profit = $my_finances->getProfit();
Solution no. 3: (avoid using!)
function expenditure() {
global $sum1, $sum2;
return $sum1 + $sum2;
}
function income() {
global $sum1, $sum2;
return $sum1 + $sum2;
}
And then you use it like that:
$sum1 = 10;
$sum2 = 200;
$expenditure = expenditure();
$sum1 = 20;
$sum2 = 30;
$income = income();
$profit = $income - $expenditure;
I hope you see, why the Solution no. 3 is such a bad idea (as generally using global variables to pass something to function is bad idea).

Answer 3

This relates to another problem, that you may face at a later stage. What if you wanted to pass 2 variables in a function and change both their values.
$var1 = 22;
$var2 = 15;
function multi2(&$x, &$y){
$x = $x * 2;
$y = $y * 2;
}
multi2($var1, $var2);
print $var1 . ", " . $var2;
You will get this as an output
44, 30
The $x and $y parameters are not a variable themselves, but a reference (defined by &) to the variables passed through, this is helpful if you require to change the values external variables internally.
Link to understand more http://php.net/manual/en/language.references.pass.php