WooCommerce Quality Selector

add_action( 'woocommerce_after_add_to_cart_quantity', 'ts_quantity_plus_sign' );

function ts_quantity_plus_sign() {

   echo '<button type="button" class="plus w-btn us-btn-style_6" >+</button>';

}

add_action( 'woocommerce_before_add_to_cart_quantity', 'ts_quantity_minus_sign' );

function ts_quantity_minus_sign() {

   echo '<button type="button" class="minus w-btn us-btn-style_6" >-</button>';

}

add_action( 'wp_footer', 'ts_quantity_plus_minus' );

function ts_quantity_plus_minus() {

   // To run this on the single product page

   if ( ! is_product() ) return;

   ?>

   <script type="text/javascript">

      jQuery(document).ready(function($){   

            $('form.cart').on( 'click', 'button.plus, button.minus', function() {

            // Get current quantity values

            var qty = $( this ).closest( 'form.cart' ).find( '.qty' );

            var val   = parseFloat(qty.val());

            var max = parseFloat(qty.attr( 'max' ));

            var min = parseFloat(qty.attr( 'min' ));

            var step = parseFloat(qty.attr( 'step' ));

            // Change the value if plus or minus

            if ( $( this ).is( '.plus' ) ) {

               if ( max && ( max <= val ) ) {

                  qty.val( max );

               } 

            else {

               qty.val( val + step );

                 }

            } 

            else {

               if ( min && ( min >= val ) ) {

                  qty.val( min );

               } 

               else if ( val > 1 ) {

                  qty.val( val - step );

               }

            }

         });

      });

   </script>

   <?php

}

?>