SEARCH KEYWORD -- pseudo-element


  jQuery to check whether checkbox is checked

In Vanilla JavaScript, the correct way of checking whether a checkbox is checked is to get the property checked of the checkbox. Assuming there is an checkbox with id "checkbox1", below line will return true if the checkbox is checked while it will return false if the checkbox is unchecked: document.getElementById("checkbox1").checked In jQuery, there are a few ways to check this. The first one is to using the corresponding counterpart of the Vanilla JavaScript, it is to check the checked proper...

   jQuery,checked,checkbox,attr,prop     2015-07-25 08:49:54

  Tips to improve JavaScript efficiency

Writing JavaScript code is tedious and error prone. You not only need to implement the necessary functions, but also need to ensure cross browser compatibility. This often causes the low efficiency of JavaScript developers. Here we recommend 12 tips you can benefit from. 1. Remove array element by index If we want to remove one element in an array, we can use splice. function removeByIndex(arr, index) { arr.splice(index, 1); } test = new Array(); test[0] = ’Apple’; test[1] = &rsq...

   JavaScript,Tips,Array     2013-07-27 20:50:40

  Use CSS calc to align an element vertically

calc function is a function introduced in CSS3, it can be used to calculate length values. There are a few good features which make it suitable for aligning an element vertically. One good part is that the operands can have different units like percentage, px, rem etc. This makes it very flexible when calculating the length value. One example: .rect{ margin-top:20px; height:50px; background:green; width:calc(100%-20px); } Here the left operand uses percentage while the right one ...

   CSS3,CALC,VERTICAL ALIGN     2019-08-23 20:30:23

  How to check whether a web page can be loaded in iframe

Sometimes you may want to load other website's page in your own website's iframe, but due to some security concerns, other website may have security configurations which prevent you from loading their pages into your iframe. In this case, if you try to load them, you would see a blank page or a text message telling that it's prohibited. Fortunately, you can detect this before you actually decide to load it. To prevent a page from being loaded by an iframe from other site, the response ...

   HTTP,HTML,IFRAME,SECURITY,X-FRAME-OPTIONS,CONTENT-SECURITY-POLICY     2018-07-27 22:36:02

  The internals of slice in GoLang

There are 3 components of slice:a) Pointer: Points to the start position of slice in the underlying array;b) length (type is int): the number of the valid elements of the slice;b) capacity (type is int): the total number of slots of the slice. Check the following code: package main import ( "fmt" "unsafe" ) func main() { var s1 []int fmt.Println(unsafe.Sizeof(s1)) } The result is 24 on my 64-bit system (The pointer and int both occupy 8 bytes). In the next example, I will use gdb to poke t...

   GOLANG,SLICE     2019-06-30 02:55:22

  Ways to make elements in HTML center aligned horizontally

In our daily HTML design,  it is an easy job to horizontally center align an element with known width. <div class="element">I am<a href="http://www.aiubug.com" target="_blank" rel="external" title=""> bug </a>！</div>  .element{width:960px;margin:0 auto;}  The above codes set the width of the div block and horizontally center align it. It's very easy to implement. However, if we have some elements we don;t know their width and we still want to...

   HTML,CSS,Center align,Unknown width     2012-07-11 12:55:00

  The danger of target=_blank and opener

When want to open a new page in a new tab on clicking a link on a page, the usual way of achieving this is to use target="_blank" property in a tag. However, the use of this leaves space for phishing website. Background parent and opener Before talking about the opener object, let's know a bit about parent object when using iframe. HTML provides a parent object which is used to communicate between the parent page and the embedded iframe element. This parent object can be accessed using...

   HTML,TARGET BLANK,REL NOOPENER,REL NOREFERRER     2018-09-15 04:53:56

  SkipList in Go

Algorithmic thinking is the must-have in the coding world, so I have been keeping the routine of algorithm practice every week, consolidating my knowledge of data structures on one hand, and improving my coding skills as well. A difficult one happened to be stuck in my mind- Implement SkipList with Go, which took me quite a weekend. Below is the front-line report of how I finally got the hang of it. First, from its concept. Wiki has explained it well. a skip list is a probab...

   GOLANG,SKIPLIST     2022-04-05 02:21:59

  Why accessing Java HashMap may cause infinite loop in concurrent environment

HashMap in Java is frequently used to handle key/value pairs. But it is not a good candidate to be used in concurrent environment where ConcurrentHashMap should be used instead. If used in concurrent environment, it may cause lots of unexpected behavior even including make the program getting into an infinite loop situation. To understand how this can happen, let's first discuss how HaspMap works internally. In this post we will use implementation of HashMap before Java 8 as example, Java 8 prov...

   JAVA,HASHMAP,INFINITE LOOP     2020-03-29 01:47:00

  How to be jQuery-free?

jQuery is now the most famous JavaScript library. There are around 57.3% websites in the world using jQuery, i.e, 6 out of 10 websites are using jQuery. If we only consider those websites which use libraries, then the percentage is even higher which is 91.7%. Although jQuery is very popular, its size is still a headache to many websites maintainers. The uncompressed jQuery 2.0 has a size of 235KB, the size is 81KB after optimization.The jQuery 1.8.3 which supports IE 6/7/8 has a uncompressed si...

   jQuery,JavaScript,ECMAScript,CSS3     2013-05-13 11:53:20

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