Conditional based on values for single-value fields (radio buttons, select, etc)
For regular WordPress post meta: <?php $customfield = get_post_meta($post->ID, 'custom_field', true); if ( $customfield == 'textstring' ) { do stuff } ?> For ACF: <?php $customfield = get_field('custom_field'); if ( $customfield == 'textstring' ) { do stuff } ?> for ACF repeater subfield: <?php $customfield = get_sub_field('custom_field'); if ( $customfield == 'textstring' ) { do stuff } ?>