输入框动态增加和删除并重新编号：
代码附上：
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>添加元素</title><script src="jquery-3.3.1.js"></script><script>var i = 1;$(function () {$("#box").on('click','.addp',function () {//$('#pp').after($("#pp").clone());var addP = $(this).parent().clone();$(this).parent().after(addP);$('#pp a').each(function (i,e) {$(e).text(i+1);})});$("#box").on("click",'.delp',function () {$(this).parent().remove();$('#pp a').each(function (i,e) {$(e).text(i+1);})})});</script></head><body><div id="box"><p id="pp"><a>1</a><input type="text" name="gx"><button class='addp'>+</button><button class='delp'>-</button></p></div></body></html>
效果图：
