JS基于递归实现倒计时效果的方法

//发送验证码
$('.js-sms-code').click(function(){
 $(this).attr("disabled", "disabled").html("<span style='color:#666'><span id='countdown'>60</span>s 后再试</span>");
 countdown();
 var tel = $('#tel').val();
 $.ajax({
 url: "{sh::U('Home/sendSmscode')}",
 type:'POST',
 dataType:"json",
 data: {tel: tel},
 success: function() {
 },
 error: function() {
 $('.js-help-info').html("请求失败");
 }
 });
})

function countdown() { // 递归
 setTimeout(function() {
 var time = $("#countdown").text();
 if (time == 1) {
 $('.js-sms-code').removeAttr("disabled");
 $('.js-sms-code').html("发送验证码");
 } else {
 $("#countdown").text(time - 1);
 countdown();
 }
 }, 1000);
}