Variable loss even with global attribute - eval() method - PHP

Question

I am stuck with a variable issue:

I will provide directly some code so that you can understand

global $myVar;
setVar('test');
function setVar($value) {
    eval('$myVar = \' '. $value .' \';');
    echo $myVar; //Here myVar is set to $vaue=test
}
echo $myVar; //Here the variable gets back to null, no output at all!

why ? I need to find a solution

EDIT:

I NEED ABSOLUTELY eval() method due to a for loop which needs to evaluate variables

Answer 1

you have to declare the variable as a global in the function as well.

function setVar($value) {
  global $myVar;
  eval('$myVar = \' '. $value .' \';');
  echo $myVar;
}

Answer 2

global only works inside a function. it does not magically make a variable "superglobal" like you're trying:

$myvar = 'foo';
function setVar($value) {
    global $myvar;   // <---global must be used here INSIDE the function
    $myvar = $value;
}

There is absolutely no need for eval() in your code, and I strongly advise you NEVER to use it. Especially when starting out.