如何在函数内部使用foreach

I am having the darndest time figuring out how to use a foreach inside a function.I have rewritten my code down to the simplest form and still cannot get it to run. This is the simple version of what I am trying to do:

$arr = array("first","second","third");
function myFunction(){
  foreach($arr as $val){
    echo $val.' | ';
  }

}
myFunction();

I know the solution must be one of those "doh" moments but I must risk embarrassment 'cause I can't get it...

In PHP global variables need to be said inside the function. You simply need to say you using a global variable otherwise PHP won't know. So you just need to add global $arr; like so:

$arr = array("first","second","third");
function myFunction(){
    global $arr; // <-- This states we are using the $arr defined globally.
    foreach($arr as $val){
      echo $val.' | ';
    }
}
myFunction();

$arr = array("first","second","third");
function myFunction($target){
  foreach($target as $val){
    echo $val.' | ';
  }

}
myFunction($arr);//$arr will send to function for process

Have a try!

You can also pass array to the function.

 $arr = array("first","second","third");
 function myFunction($arr){
   foreach($arr as $val){ 
     echo $val.' | ';
   }

 }
 myFunction($arr);