php 理解动作的概念并在wordpress中过滤

Posted 2021-05-05

##Now understand this code:-
1. First we create a sample array of fruits with two key value pair.
2. Now seconds line shows that to modify this array we create a filter  which we name as `amrt_cust`.
3. Simple by passing the "name" as first param & "variable to modify" on second param.
4. So think it as some variable whose value is required at many points and we want to chnage it at some certain actions, so we need to accomplish this using filters in wordpress.
5. Now when we created a filter, lets use it and modify the data.
6. we going to use `add_filter()` for this, this function takes the name of already created filter as first param and <i>callback</i> function as second.
7. If you see in the defination of callback function we use one argument. Now the logic is, no. of arguments can be used is equal to the no. of variable to change in `apply_filter()` function.
8. So in this callback function what we did, change the value of second key in this array. Now understand this , when we changed the value, it got change globelly. Which means in your one php execuation the chnaged value will get procceded as $array.

Thanks!

$array = array(
    0 => 'orange',
    1 => 'banana'
);

apply_filters('amrt_cust', $array);

function applynow($array) {
    $array[1] = 'grapes';
    print_r($array);
    die;
}

add_filter('amrt_cust', 'applynow');