User function to return multiple get_post_meta()

Question

I am trying pass a WP function to a user function, where I can pass a new func argument $key for each post_meta type here:

functions.php

  function my_post_meta($key){
      $meta = get_post_meta($post->ID, $key, true); 
      if ($meta) {
       echo $meta . '<br />';           
     }  
   }

page-template.php

Edit: These functions will be inside a foreach() of get_posts().

my_post_meta("Author");
my_post_meta("Date") .'customise this meta key';
my_post_meta("Address") .'customise this meta key';

Answer 1

The second and third argument to get_post_meta() are optional. If not provided-- ie. get_post_meta($post->ID)-- you will get an array of all meta for the post.

If only $id is set it will return all meta values in an associative array.

http://codex.wordpress.org/Function_Reference/get_post_meta#Return_Value

For example:

$meta = get_post_meta($post->ID); 
var_dump($meta);

Answer 2

As I wanted to put the if() statement into a function - continuing on from s_ha_dum's help, here is my own answer. I included the second argument so as only return the keys I need.

I am passing the NULL value to two of my function arguments as way to make them optional as suggested here: ... optional parameter values in PHP.

functions.php

function jd_post_meta($strongstart = NULL, $key, $strongend = NUll){
  global $post;
  $meta = get_post_meta($post->ID, $key);
  if($meta[0]) {
    echo $boldstart.$meta[0].$boldend.'<br />';
  }
}   

page-template.php

jd_post_meta(NULL,'Author',NULL);
jd_post_meta('Translation <strong>','Translator','</strong>');
jd_post_meta(NULL,'Event-date',NULL);
jd_post_meta(NULL,'Event-address',NULL);