Algorithm, which is difficult for conditional running of custom functions. Thanks

It is difficult to find an algorithm for conditional execution of user-defined functions. Thank you! In PHP, you need to find an algorithm. for example, $ arr0, $ arr1, and $ arr2, $ arr3, the number of elements is fixed by 4, $ arr0 = array ('', 'wc1','', 'wc3'); // This array is defined, it is difficult to evaluate an algorithm for executing those functions and methods $. Thank you!

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  In PHP, please find an algorithm. for example: $ arr0, $ arr1 and $ arr2, $ arr3, the number of elements is fixed 4, $ arr0 = array ('', 'wc1','', 'wc3'); // This array is defined, to execute those functions and methods $ arr1 = array ('wc0 ', 'wc1', 'wc2', ''); $ arr2 = array ('wc0 ','', '', 'wc3'); a total of four custom functions, namely function wc0 () {} function wc1 () {} function wc2 () {} function wc3 () {} problem start: For arrays $ arr0, $ arr1, and $ arr2, when the element is not empty, the corresponding user-defined function is executed. For example: when $ arr0 = array ('', 'wc1','', 'wc3') is encountered, two functions are executed: wc1 () and wc3 () when $ arr1 = array ('wc0 ', 'wc1', 'wc2 ', '') is encountered, three functions are executed: wc0 (), wc1 (), wc2 () when $ arr2 = array ('wc0 ', '','', 'wc3') is encountered, two functions are executed, wc0 (), wc3 ()....... do you see the rule? That's exactly what it looks like. now I want to rewrite it into a function and find an algorithm. That is, when $ arr is encountered, XXXX is executed.

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Function wc0 () {echo "wc0 \ n";} function wc1 () {echo "wc1 \ n";} function wc2 () {echo "wc2 \ n ";} function wc3 () {echo "wc3 \ n" ;}$ arr = array ('', 'wc1','', 'wc3 '); foreach ($ arr as $ func) {if (function_exists ($ func) {$ func ();}}
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Either array_product or array_reduce can be used.

For
$ Ar = array ('', 'wc1','', 'wc3 ');
$ R = array ();
Foreach ($ ar as $ func)
$ R [] = $ func? $ Func (): 1;
Echo array_product ($ r );

& Equal to multiplication
Assume that wc1 returns 0 and wc3 returns 1.
Then, the value of $ r is 1, 0, and the value is 0 after the multiplication of 1, 1, and 1.

Assume that wc1 returns 1 and wc3 returns 1.
Then, $ r is, and 1 is obtained after multiplication.

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This is relatively simple.

    

     
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$a=Array('a','b','','c');For($i=0;$i<4;$i++) {    IF($a[$i]!='') {        eval("wc{$i}();");    }}function wc0(){    Echo '0';}function wc1(){    Echo '1';}function wc2(){    Echo '2';}function wc3(){    Echo '3';}