call function through variable??

[yuan]

function output1() {
    echo "Today is ".date('Y-m-d');
}

function output2() {
    echo "Time is ".date('H:i:s');
}

May i know how to call the function through variable?

"output".$_GET['id']; //i had try this, but it can't work

[tekky]

use return....

function myFunc() {
  return 'Today is '.date('Y-m-d');
}

$myVar = 'This is my string + myFuncs output combined: ' . myFunc();

[yuan]

tekky wrote:

use return....

function myFunc() {
  return 'Today is '.date('Y-m-d');
}

$myVar = 'This is my string + myFuncs output combined: ' . myFunc();

Thanks tekky, but the main point is how to decide which function to be call by $_GET['id'] such as :

$myVar = 'This is my string + myFuncs output combined: ' . myFunc.$_GET'id';

except using if condition

[laserlight]

Thanks tekky, but the main point is how to decide which function to be call by $GET['id']

Check the value of $GET['id']

function output1() {
    echo "Today is ".date('Y-m-d');
}

function output2() {
    echo "Time is ".date('H:i:s');
}

if (isset($_GET['id'])) {
	if ($_GET['id'] == 0) {
		output1();
	} else {
		output2();
	}
} else {
	echo 'id not set';
}

It looks like you are trying to use variable functions, but in this case, with incoming variables, it is better done by checking values and calling the appropriate function.

[yuan]

I found the way to solve this problem, sorry for disturbing

$func = 'myFunc'.$_GET['id'];
$func();

[laserlight]

That way is the use of variable functions. Not a good idea since $_GET['id'] is an incoming variable. You must check and validate incoming variables before using them, even more so if they are directly affecting your code.

[yuan]

laserlight wrote:

Check the value of $_GET['id']

function output1() {
    echo "Today is ".date('Y-m-d');
}

function output2() {
    echo "Time is ".date('H:i:s');
}

if (isset($_GET['id'])) {
	if ($_GET['id'] == 0) {
		output1();
	} else {
		output2();
	}
} else {
	echo 'id not set';
}

It looks like you are trying to use variable functions, but in this case, with incoming variables, it is better done by checking values and calling the appropriate function.

Thanks for laserlight, i'm annoying to use if condition. But anyway, i found the way to solve it 😃

[laserlight]

i found the way to solve it

You are introducing a potential security loophole.

If you really do want to use variable functions, then you must check:

if (in_array($_GET['id'], array('output1', 'output2'))) {
	$func = 'myFunc' . $_GET['id'];
	$func();
}

[yuan]

laserlight wrote:

You are introducing a potential security loophole.

If you really do want to use variable functions, then you must check:

if (in_array($_GET['id'], array('output1', 'output2'))) {
	$func = 'myFunc' . $_GET['id'];
	$func();
}

Thanks laserlight 🙂 , i'll remember it

[laserlight]

hmm... haha, I could have been too conscientious there. In your case, it looks like you are only passing numeric ids in the incoming variable. As such, a security exploit is much less likely. You still need to check that the number is valid, of course.

[bradgrafelman]

Still, if you don't use [man]intval/man or some other method of verification to make sure it's an integer, you could still cause some odd things to happen.