In the javascript-ajax return value, some inexplicable blank lines will appear in the first place.

I am using wordpress. I don't know why some blank lines will appear in the returned results. Jquery {code...} PHP {code ...}

I am using wordpress. I don't know why some blank lines will appear in the returned results.

Jquery

$.ajax({        type:'post',        url:localcurrent.ajax_url,        data:favorite_data,        success:function(response){            alert(response);        }    });

PHP

Function favorite_post () {$ post_id = $ _ POST ["post_id"]; $ user_id = get_current_user_id (); $ favorite = favorite_get ($ post_id, 1 ); // determine whether the user has added this article to the favorites if (! In_array ($ user_id, $ favorite) {// This item is not added to the user's favorites. To add the favorites favorite_add ($ user_id, $ post_id); echo 'add'; exit ;} else {// The user has added this item to favorites. To remove the added item from favorites, favorite_del ($ user_id, $ post_id); echo 'delete'; exit;} echo 'error'; exit ;} add_action ('wp _ ajax_favorite_post', 'favorite _ Post ');

Reply content:

I am using wordpress. I don't know why some blank lines will appear in the returned results.

Jquery

$.ajax({        type:'post',        url:localcurrent.ajax_url,        data:favorite_data,        success:function(response){            alert(response);        }    });

PHP

Function favorite_post () {$ post_id = $ _ POST ["post_id"]; $ user_id = get_current_user_id (); $ favorite = favorite_get ($ post_id, 1 ); // determine whether the user has added this article to the favorites if (! In_array ($ user_id, $ favorite) {// This item is not added to the user's favorites. To add the favorites favorite_add ($ user_id, $ post_id); echo 'add'; exit ;} else {// The user has added this item to favorites. To remove the added item from favorites, favorite_del ($ user_id, $ post_id); echo 'delete'; exit;} echo 'error'; exit ;} add_action ('wp _ ajax_favorite_post', 'favorite _ Post ');

I think there are two situations:
1. Something in the PHP template as mentioned above.
2. The returned data contains UTF-8 text in BOM format.

Is the php tag deleted at the top of the php template file? I did the same before. After checking for a long time, I found that I deleted some things at the top of the template file.

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