关于javascript:数组按id分类

var list = [       { id: '1', name: 'test1', rName: 'the1' },       { id: '1', name: 'test1', rName: 'the2' },       { id: '1', name: 'test1', rName: 'the3' },       { id: '2', name: 'test2', rName: 'the1' },       { id: '2', name: 'test2', rName: 'the2' },       { id: '3', name: 'test3', rName: 'the1' },       { id: '4', name: 'test3', rName: 'the1' },       { id: '5', name: 'test3', rName: 'the1' },     ]     var list2 = []     for (var i in list) {       var list3 = []       for (var j in list) {         if (list[i].id == list[j].id && list[j].key != 1) {           list[j].key = 1           list3.push(list[j])         }       }       if (list3.length > 0) {         list2.push(list3)       }     }     console.log('2222', list2)