Js if 在 setInterval() 中不起作用

Question

您好！

我的网站上有这个：

  var docCookies = {
  getItem: function (sKey) {
  if (!sKey) { return null; }
  return decodeURIComponent(document.cookie.replace(new RegExp("(?:(?:^|.*;)\s*" + encodeURIComponent(sKey).replace(/[\-\.\+\*]/g, "\$&") + "\s*\=\s*([^;]*).*$)|^.*$"), "")) || null;
 },
 setItem: function (sKey, sValue, vEnd, sPath, sDomain, bSecure) {
 if (!sKey || /^(?:expires|max\-age|path|domain|secure)$/i.test(sKey)) {return false; }
var sExpires = "";
if (vEnd) {
  switch (vEnd.constructor) {
    case Number:
      sExpires = vEnd === Infinity ? "; expires=Fri, 31 Dec 9999 23:59:59 GMT" : "; max-age=" + vEnd;
      break;
    case String:
      sExpires = "; expires=" + vEnd;
      break;
    case Date:
      sExpires = "; expires=" + vEnd.toUTCString();
      break;
  }
}
document.cookie = encodeURIComponent(sKey) + "=" + encodeURIComponent(sValue) + sExpires + (sDomain ? "; domain=" + sDomain : "") + (sPath ? "; path=" + sPath : "") + (bSecure ? "; secure" : "");
return true;
},
removeItem: function (sKey, sPath, sDomain) {
if (!this.hasItem(sKey)) { return false; }
document.cookie = encodeURIComponent(sKey) + "=; expires=Thu, 01 Jan 1970 00:00:00 GMT" + (sDomain ? "; domain=" + sDomain : "") + (sPath ? "; path=" + sPath : "");
return true;
},
hasItem: function (sKey) {
if (!sKey) { return false; }
return (new RegExp("(?:^|;\s*)" + encodeURIComponent(sKey).replace(/[\-\.\+\*]/g, "\$&") + "\s*\=")).test(document.cookie);
},
keys: function () {
var aKeys = document.cookie.replace(/((?:^|\s*;)[^\=]+)(?=;|$)|^\s*|\s*(?:\=[^;]*)?(?:|$)/g, "").split(/\s*(?:\=[^;]*)?;\s*/);
for (var nLen = aKeys.length, nIdx = 0; nIdx < nLen; nIdx++) { aKeys[nIdx] = decodeURIComponent(aKeys[nIdx]); }
return aKeys;
}
};

alert('In next prompt enter "admin".')

var admin = prompt('Name?')

docCookies.setItem('name',admin);

setInterval(function() {if (docCookies.getItem('name')){}else{var a = 2}}, 1000)

但这行不通：

setInterval(function() {if (docCookies.getItem('name')){}else{var a = 2}}, 1000)

为什么这不起作用：

setInterval(function() {if (docCookies.getItem('name')){}else{var a = 2}}, 1000)

页面中的哪些内容不起作用，为什么？我

<script type="text/javascript">
  var docCookies = {
  getItem: function (sKey) {
    if (!sKey) { return null; }
    return decodeURIComponent(document.cookie.replace(new RegExp("(?:(?:^|.*;)\s*" + encodeURIComponent(sKey).replace(/[\-\.\+\*]/g, "\$&") + "\s*\=\s*([^;]*).*$)|^.*$"), "")) || null;
  },
  setItem: function (sKey, sValue, vEnd, sPath, sDomain, bSecure) {
    if (!sKey || /^(?:expires|max\-age|path|domain|secure)$/i.test(sKey)) { return false; }
    var sExpires = "";
    if (vEnd) {
      switch (vEnd.constructor) {
        case Number:
          sExpires = vEnd === Infinity ? "; expires=Fri, 31 Dec 9999 23:59:59 GMT" : "; max-age=" + vEnd;
          break;
        case String:
          sExpires = "; expires=" + vEnd;
          break;
        case Date:
          sExpires = "; expires=" + vEnd.toUTCString();
          break;
      }
    }
    document.cookie = encodeURIComponent(sKey) + "=" + encodeURIComponent(sValue) + sExpires + (sDomain ? "; domain=" + sDomain : "") + (sPath ? "; path=" + sPath : "") + (bSecure ? "; secure" : "");
    return true;
  },
  removeItem: function (sKey, sPath, sDomain) {
    if (!this.hasItem(sKey)) { return false; }
    document.cookie = encodeURIComponent(sKey) + "=; expires=Thu, 01 Jan 1970 00:00:00 GMT" + (sDomain ? "; domain=" + sDomain : "") + (sPath ? "; path=" + sPath : "");
    return true;
  },
  hasItem: function (sKey) {
    if (!sKey) { return false; }
    return (new RegExp("(?:^|;\s*)" + encodeURIComponent(sKey).replace(/[\-\.\+\*]/g, "\$&") + "\s*\=")).test(document.cookie);
  },
  keys: function () {
    var aKeys = document.cookie.replace(/((?:^|\s*;)[^\=]+)(?=;|$)|^\s*|\s*(?:\=[^;]*)?(?:|$)/g, "").split(/\s*(?:\=[^;]*)?;\s*/);
    for (var nLen = aKeys.length, nIdx = 0; nIdx < nLen; nIdx++) { aKeys[nIdx] = decodeURIComponent(aKeys[nIdx]); }
    return aKeys;
  }
};

alert('In next prompt enter "admin".')

var admin = prompt('Name?')

docCookies.setItem('name',admin);

setInterval(function() {if (docCookies.getItem('name')){}else{var a = 2}}, 1000)

Answer 1

变量是在函数局部声明的，所以它只存在于那个作用域内，并且只存在于函数运行.

在全局范围内声明变量，以便您可以在任何地方设置和读取它：

var a;

setInterval(function() {
  if (!docCookies.getItem('name')) {
    a = 2;
  }
}, 1000)

Js if 在 setInterval() 中不起作用

Js if is not work in setInterval()

function

if-statement

setinterval

js-cookie

您好！