How to create shortcodes in functions.php

function be_biz_grid() {


$content="Welcome to the biz grid."
return $content;

}
add_shortcode('biz-grid', 'be_biz_grid'); 


//using ob_start there is no need to store everything in the content variable.

function be_biz_grid() {
ob_start();

... code here  ...
$content = ob_get_clean();
return $content;
}
add_shortcode('biz-grid', 'be_biz_grid');