unable to increment static vaue in PHP - php

Question

I am trying to print score automatically, if the question is correct it should increment the score. I tried this function:
function checkscore ()
{
static $score = 0;
if ($_SESSION['result'] == "Correct")
$score++;
return $score;
}
this function returns 1 if the question is correct or 0 if the question is wrong. But $score does not increment in any case. How can I make increment the $score variable?

Answer 1

Do not init $score variable, like this:
function checkscore ()
{
static $score; // Here without initialization
if (is_null($score)) {
$score = 0;
}
if ($_SESSION['result'] == "Correct") {
$score++;
}
return $score;
}
$_SESSION['result'] = 'Correct';
checkscore(); // 1
checkscore(); // 2
...

Answer 2

There is nothing wrong with your code but I imaging you are expecting the static variable to remain in existance over multiple calls to this script.
That is not how static works!
If you use it like this:
function checkscore ()
{
static $score = 0;
if ($_SESSION['result'] == "Correct")
$score ++;
return $score;
}
echo checkscore () . '<br>';
echo checkscore () . '<br>';
echo checkscore () . '<br>';
You will get the result:
1
2
3
But if you are calling the script from a form where the user answers ONE question and the form is submitted to this script static will not work as you expect. The static variable will be initialised to zero on each call to the script.
If you want to remember the value of $score across multiple calls to the script you will have to save it in the $_SESSION something like this
function checkscore ()
{
$score = isset($_SESSION['score']) ? $_SESSION['score'] : 0;
if ($_SESSION['result'] == "Correct")
$score ++;
$_SESSION['score'] = $score;
return $score;
}

Answer 3

You need to pass the variable as the argument of function.Try like this
function checkscore ($score){
if ($_SESSION['result'] == "Correct")
$score ++;
return $score;
}
//Function call example;
checkscore (1);

Answer 4

static variable gets initialized only once even re-initialization will not effect value of variable, A static variable exists only in a local function scope, but it does not lose its value when program execution leaves this scope.
function checkscore ()
{
static $score = 0;
if ($_SESSION['result'] == "Correct")
$score++;
return $score;
}
Nothing wrong with your code check wether you may be doing it wrong on the calling section or handling return value.

Answer 5

You can try this also, pass by refrence
function checkscore (&$score){
if ($_SESSION['result'] == "Correct"){
$score ++;
return 'correct';
}else{
return 'wrong';
}
//Function call example;
$score = 1;
checkscore ($score);
echo $score;
In this way you will return two values from a function one will say correct or wrong and reference variable will update score as well.