如下面的數組， 希望得到[{name: 'zhang', conut: 4},{name: 'wang', conut: 2},{name: 'liu', conut: 2}],或者[{zhang: 4},{wang: 2},{liu: 2}]謝謝了let arr= [             {name: 'zhang', age: '20'},             {name: 'wang', age: '22'},             {name: 'zhang', age: '20'},             {name: 'liu', age: '23'},             {name: 'liu', age: '23'},             {name: 'wang', age: '22'},             {name: 'zhang', age: '20'},             {name: 'zhang', age: '20'},         ]