js实现单选

    span {
        width: 100px;
        text-align: center;
        line-height: 30px;
        border: 1px solid #ddd;
        background-color: #eee;
        display: inline-block;
    }

    .active {
        border: 1px solid red;
        color: red
    }

var btns = document.querySelectorAll(‘span’);
console.log(btns);
// 绑定点击事件
for (var i = 0; i < btns.length; i++) {
btns[i].onclick = function () {
for (var j = 0; j < 3; j++) {
btns[j].setAttribute(‘class’, ‘’);
}
this.setAttribute(‘class’, ‘active’)

            // for(var j = 0 ; j < 3 ; j++){
            //     div[j].setAttribute('class','');
            // }
            // this.setAttribute('class','show')

        }
    }