题解 | #数组过滤#

    <script>
        var cups = [
            { type: 1, price: 100, color: 'black', sales: 60, name: '牛客logo马克杯' },
            { type: 2, price: 40, color: 'blue', sales: 100, name: '无盖星空杯' },
            { type: 4, price: 60, color: 'green', sales: 200, name: '老式茶杯' },
            { type: 3, price: 50, color: 'green', sales: 600, name: '欧式印花杯' }
        ]
        var select = document.querySelector('select');
        var ul = document.querySelector('ul');
        // 补全代码
        select.onchange=function(){
            ul.innerHTML=''
            switch(parseInt(this.value)){
                case 1:
                var newArr=cups.filter(item=>item.sales<100)
                break
                case 2:
                var newArr=cups.filter(item=>item.sales>=100&&item.sales<=500)
                break
                case 3:
                var newArr=cups.filter(item=>item.sales>500)
                break
            }
           arr2string(newArr)
        }

        function arr2string(arr){
            var str=''
            arr.forEach(item=>{
                str+=`<li>${item.name}</li>`
            })
            ul.innerHTML=str
        }
    </script>  

看了题解发现是sales不是price