This question already has an answer here: Detecting an undefined object property 40 answers How to determine if variable is 'undefined' or 'null'? 24 answers Using typeof : if (typeof marcamillion == 'undefined') { console.log("Marcamillion is an undefined variable."); } Edit for the second question: if ($(this).attr('value')) { // code } else { console.log('
这个问题在这里已经有了答案： 检测未定义的对象属性40个答案 如何确定变量是'undefined'还是'null'？ 24个答案 使用typeof ： if (typeof marcamillion == 'undefined') { console.log("Marcamillion is an undefined variable."); } 编辑第二个问题： if ($(this).attr('value')) { // code } else { console.log('nope.') } if (typeof marcamillion === 'undefined') { console.lo
This question already has an answer here: Detecting an undefined object property 40 answers If an object's property may refer to some other object then you can test that for undefined before trying to use its properties: if (thing && thing.foo) alert(thing.foo.bar); I could update my answer to better reflect your situation if you show some actual code, but possibly something
这个问题在这里已经有了答案： 检测未定义的对象属性40个答案 如果一个对象的属性可能引用某个其他对象，那么您可以在尝试使用它的属性之前对其进行测试： if (thing && thing.foo) alert(thing.foo.bar); 我可以更新我的答案，以更好地反映你的情况，如果你显示一些实际的代码，但可能是这样的： function someFunc(parameterName) { if (parameterName && parameterName.foo) alert(parame
I am trying to create a WinJS.UI.Flyout with a single input field and a single button to allow the user to enter a new value in the input field and click on the button to save it. However, on windows phone 8.1, Flyouts are not supported. How can I work around that? Is there a way to mimic the behavior of the WinJS.UI.Flyout component on phone 8.1? Thanks in advance. Personal opinion on ar
我正尝试创建一个带有单个输入字段和单个按钮的WinJS.UI.Flyout，以允许用户在输入字段中输入一个新值并单击该按钮进行保存。 但是，在Windows Phone 8.1上，Flyouts不受支持。 我该如何解决这个问题？ 有没有办法模仿手机8.1上的WinJS.UI.Flyout组件的行为？ 提前致谢。 个人对这里的体系结构的看法，但我相信如果你要有一个提示的API，并且你希望人们真正使用它，你需要确保它在所有环境中都受到支持。 以下是我用于
I've made a simple website that works fine on localhost. So I've put it on an IIS Windows 2008r2 server and now my PHP scripts don't write to my JSON files anymore. I've checked the server and PHP is installed on it so I don't really know what's wrong or where to look. I'm still not getting it to work so thought I'd explain the situation in more detail. So th
我做了一个简单的网站，在本地主机上正常工作。 所以我把它放在IIS Windows 2008r2服务器上，现在我的PHP脚本不再写入我的JSON文件了。 我已经检查过服务器并安装了PHP，所以我不知道发生了什么问题或在哪里寻找。 我仍然没有得到它的工作，所以认为我会更详细地解释情况。 所以这个脚本在本地主机上工作，但不在IIS服务器上。 <?php $myFile = "../json/countries.json"; $fh = fopen($myFile, 'w') or die("can't ope
It seems like the point of window.postMessage is to allow safe communication between windows/frames hosted on different domains, but it doesn't actually seem to allow that in Chrome. Here's the scenario: Embed an <iframe> (with a src on domain B*) in a page on domain A The <iframe> ends up being mostly a <script> tag, at the end of which's execution... I call
看起来window.postMessage的要点是允许在不同域上托管的窗口/框架之间进行安全通信，但实际上Chrome并没有允许这样做。 以下是该场景： 在域A的页面中嵌入<iframe>（在域B *上带有src ） <iframe>最终是一个<script>标签，在其结束时执行... 我打电话给window.postMessage（some_data，page_on_A） <iframe>绝对是在域B的上下文中，并且我已经确认在<iframe>中嵌入的javascript可以正确
What is the correct way to pull out just the path from a URL using JavaScript? Example: I have URL http://www.somedomain.com/account/search?filter=a#top but I would just like to get this portion /account/search I am using jQuery if there is anything there that can be leveraged. There is a property of the built-in window.location object that will provide that for the current window.
使用JavaScript从URL中提取路径的正确方法是什么？ 例： 我有网址 http://www.somedomain.com/account/search?filter=a#top 但我只想获得这部分 /帐号/搜索 如果有什么可以利用的话，我正在使用jQuery。 内置的window.location对象的属性将为当前窗口提供该属性。 // If URL is http://www.somedomain.com/account/search?filter=a#top window.location.pathname // /account/search // For reference: window.
This question already has an answer here: Get the current URL with JavaScript? 18 answers In JavaScript: window.location See the link below for more info: https://developer.mozilla.org/en-US/docs/Web/API/Window.location You need to do 2 steps: open your text editor and put thest lines in it RewriteEngine On RewriteRule ^howtoloseweight/1$ /howtoloseweight/1.html [L] save file
这个问题在这里已经有了答案： 使用JavaScript获取当前网址？ 18个答案 在JavaScript中： window.location 请参阅下面的链接了解更多信息： https://developer.mozilla.org/en-US/docs/Web/API/Window.location 你需要做2个步骤： 打开你的文本编辑器，并把它的最后一行 RewriteEngine On RewriteRule ^ howtoloseweight / 1 $ /howtoloseweight/1.html [L] 保存文件为“.htaccess” 建立链接<a href=&qu
This question already has an answer here: Get the current URL with JavaScript? 18 answers 解决方案将是： var disqus_url = window.location; var disqus_url = document.location.href;
这个问题在这里已经有了答案： 使用JavaScript获取当前网址？ 18个答案 解决方案将是： var disqus_url = window.location; var disqus_url = document.location.href;
This question already has an answer here: Get the current URL with JavaScript? 18 answers window.location.href contains the current URL of the page. So your function should look like this: function twitterShare(){ window.open('http://twitter.com/intent/tweet?text=Check this out here: ' + window.location.href, "twitterWindow", "height=380,width=660,resizable=0,toolbar=0
这个问题在这里已经有了答案： 使用JavaScript获取当前网址？ 18个答案 window.location.href包含页面的当前URL。 所以你的函数应该是这样的： function twitterShare(){ window.open('http://twitter.com/intent/tweet?text=Check this out here: ' + window.location.href, "twitterWindow", "height=380,width=660,resizable=0,toolbar=0,menubar=0,status=0,location=0,scrollbars=0") retur
This question already has an answer here: Get the current URL with JavaScript? 18 answers 这是正确的答案： window.location.host + window.location.pathname; You want this: var location = window.location.host + window.location.pathname; see the docs: https://developer.mozilla.org/en-US/docs/Web/API/Location
这个问题在这里已经有了答案： 使用JavaScript获取当前网址？ 18个答案 这是正确的答案： window.location.host + window.location.pathname; 你要这个： var location = window.location.host + window.location.pathname; 请参阅文档：https：//developer.mozilla.org/en-US/docs/Web/API/Location