PHP函数引用数组

Question

I would like to check value of integer and choose function depending on this. I could do an if-elseif statement as following:

if($a==0) {function0($a);}
if($a==1) {function1($a);}

etc, but I would rather make an array of function, called maybe functionArray, which could be described as follows:

$functionArray=array( function0($a), function1($a) );

etc, so that we execute function based on $a value, which belongs to $functionArray[$a] . Is that possible? There will be over 20 functions depending on $a value, thats why I want to make it easier and avoid big if-elseif block.

Answer 1

Do not name a variable after its type. $functionArray is rather bad name for a variable, you could at least name it a collection, however, in my example I will name it just functions .

function funcOne($a) {
    echo $a+1;
}

function funcTwo($a) {
    echo $a+2;
}

$functions = array(1 => 'funcOne', 2 => 'funcTwo');

$a = 2;

$functions[$a]($a);

This might not work below PHP 5.4 and you might need additional assignation eg $calledFunction = $functions[$a]; $calledFunction($a) $calledFunction = $functions[$a]; $calledFunction($a) . Anyway, it's possible, you just need to add them as strings if you are going to use named functions.

You also can use anonymous functions to achieve that as well

$functions = array(1 => function($a) { echo $a+1; }, 2 => function($a) { echo $a+2;});

$a = 2;

$functions[$a]($a);