https://moshicom.com/assets/js/prefectures.js

1// prefectures checkbox setting
2
3$( function () {
4  $('#hokkaidoAll').on('click', function() {
5    $('.hokkaidoCheck .custom-control-input').prop('checked', this.checked);
6  });
7  $('#hokkaidoAll2').on('click', function() {
8    $('.hokkaidoCheck .custom-control-input').prop('checked', this.checked);
9  });
10  $('.hokkaidoCheck .custom-control-input').on('click', function() {
11    if ($('.hokkaidoCheck :checked').length == $('.hokkaidoCheck :input').length){
12      $('#hokkaidoAll').prop('checked', 'checked');
13    } else {
14      $('#hokkaidoAll').prop('checked', false);
15    }
16  });
17  $('.hokkaidoCheck .custom-control-input').on('click', function() {
18    if ($('.hokkaidoCheck :checked').length == $('.hokkaidoCheck :input').length){
19      $('#hokkaidoAll2').prop('checked', 'checked');
20    } else {
21      $('#hokkaidoAll2').prop('checked', false);
22    }
23  });
24
25  $('#kantoAll').on('click', function() {
26    $('.kantoCheck .custom-control-input').prop('checked', this.checked);
27  });
28  $('.kantoCheck .custom-control-input').on('click', function() {
29    if ($('.kantoCheck :checked').length == $('.kantoCheck :input').length){
30      $('#kantoAll').prop('checked', 'checked');
31    } else {
32      $('#kantoAll').prop('checked', false);
33    }
34  });
35});