代碼一：var a = b = ''a = 1console.log(a)//打印1console.log(b)//打印''代碼二：var a = b = []a.push(1)console.log(a)//打印[1]console.log(b)//打印[1]為什么代碼一兩變量不等，而代碼二兩變量相等？