How to store custom field value in variable [WordPress]

In WordPress blog we use custom fields for retrieving values from posts and pages. Here we will see how to store custom values in variables.
We have custom field for example:
Custom Field Name:SingleProduct
Custom Field Value:12345
Now we will see how we can store values using get_post_custom_values(“Custom Field Name”) function.

<?php
  $values = get_post_custom_values("SingleProduct");
  if (isset($values[0])) {
     $SingleProduct = $values[0];
} ?>

Here $values is array. get_post_custom_values function stores custom field values in array.
And then the $values[0] is stored in $SingleProduct variable.