Is it possible to check if a variable exist using a variable value? Like
//some variables:
$variable_a;
$variable_b;
$variable_c;
$variable_d;
$variable = '$variable_b';
if (the content $variable which is '$variable_b' exists == true){
}
or how to make a variable value into a variable? Like
$variable = 'variable_name'; ...some code to make 'variable_name' a variable
You can use variable variables in PHP, and then check if such a variable has a value. For instance:
$variableA = 'Hello';
$variableB = 'variableA';
echo ${$variableB};
returns Hello on your screen. You can also check if $variableA has a value by doing:
if (isset(${$variableB})) {
....
}
Note that in your question you have variables that have no value, they are not set. The whole purpose of variables is to have a value, hence their name, so your variables are some kind of zombies, not really alive, not really dead. They are not set, so isset() will return false.
