~~~ //example 1 let a = {}, b = '0', c = 0; a[b] = '珠峰'; a[c] = '培训'; console.log(a[b]); //培训 ~~~  > **为了理解可以说，对象的属性名只能是字符串，其它类型的值会先转为字符串，再去操作，但是要除去Symbol** ~~~ //example 2 let a = {}, b = Symbol('1'), c = Symbol('1'); a[b] = '珠峰'; a[c] = '培训'; console.log(a[b]); // 珠峰 ~~~   ~~~ //example 3 let a = {}, b = { n: '1' }, c = { m: '2' }; a[b] = '珠峰'; a[c] = '培训'; console.log(a[b]); //培训 ~~~