使用JavaScript实现alert的实例代码

废话不多说了，直接给大家贴代码了，具体代码如下所示：

<script>
  window.alert = alert;
  function alert(data) {
    var MainDiv = document.createElement("div"),
      p = document.createElement("p"),
      AllPage = document.createElement("div"),
      btn = document.createElement("div"),
      textNode = document.createTextNode(data ? data : ""),
      btnText = document.createTextNode("确定");
    // 控制样式
    css(AllPage, {
      "position": "fixed",
      " _position": "absolute",
      " width": "100%",
      "height": "100%",
      "left": "0",
      "top": "0",
      "background": "rgba(0, 0, 0,0.5)",
      "-moz-opacity": "0.5",
      "filter": "alpha(opacity=50)",
      "z-index": "97",
    });
    css(MainDiv, {
      "position": "fixed",
      "left": "0",
      "right": "0",
      "top": "30%",
      "width": "14rem",
      "height": "5rem",
      "padding-top":"0.5rem",
      "margin": "0 auto",
      "background-color": "white",
      "font-size": "0.75rem",
      "text-align": "center",
      "position": "relative",
      "border-radius": "5px 5px 5px 5px",
    });
    css(btn, {
      "background": "#de241b",
      "color": "white",
      "width": "6rem",
      "margin-left": "4rem",
      "margin-bottom":"0.25rem",
      "height": "1.5rem",
      "border-radius": "5px 5px 5px 5px",
      "position": "absolute",
      "padding-top":"0.5rem",
      "bottom":"0",
    })
    // 内部结构套入
    p.appendChild(textNode);
    btn.appendChild(btnText);
    MainDiv.appendChild(p);
    MainDiv.appendChild(btn);
    AllPage.appendChild(MainDiv);
    // 整体显示到页面内
    document.getElementsByTagName("body")[0].appendChild(AllPage);
    //禁止滚动
    $("body").on("touchmove", function (event) {
      event.preventDefault;
    }, false)
    // 确定绑定点击事件删除标签
    btn.onclick = function () {
      AllPage.parentNode.removeChild(AllPage);
      //启用滚动
      $("body").off("touchmove");
    }
  }
  function css(targetObj, cssObj) {
    var str = targetObj.getAttribute("style") ? targetObj.getAttribute("style") : "";
    for (var i in cssObj) {
      str += i + ":" + cssObj[i] + ";";
    }
    targetObj.style.cssText = str;
  } 

以上所述是小编给大家介绍的使用JavaScript实现alert的实例代码，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对脚本之家网站的支持！