Recently, I’ve been learning JavaScript and came across the canvas drawing section, so I created an electronic clock to practice. Each segment of the electronic clock is drawn using canvas, and then JavaScript is used to get the time, executing every millisecond to update the canvas. Demo link: http://labs.simpleapples.com/timer/ GitHub: https://github.com/simpleapples/javascripttimer
I received the first offer of my life three hours ago from a large software company in China. Two days ago, I attended the company’s presentation at my school, more out of curiosity than anything else. With the mindset of gaining experience, I participated in the on-site written test and interview. And just three hours ago, a fresh offer was placed in front of me. Oh, so this is what an offer looks like. ...
Constructor and prototype, as the names suggest, mean the builder (constructor) and the prototype. From a semantic perspective, if object A constructs object B, then A is the constructor of B. If the form of object A comes from object B, then object B is the prototype of A. Let’s look at a piece of code: function Person() { Person.prototype.name = "myname"; Person.prototype.age = 18; Person.prototype.sayName = function () { alert(this.name); }; } var person1 = new Person(); person1.sayName(); Here, Person is the constructor of Person.prototype. Why? Because Person constructed Person.prototype. However, the prototype of person1 is not Person.prototype. When person1 is initialized, it can be understood as a copy of Person (i.e., a new instance) is given to person1. Every time Person is instantiated, it inherits (just called inheritance for convenience) a copy of name, age, and sayName from its prototype. person1 is a copy of Person, but the prototype is not copied, so the prototype of person1 is undefined. ...
Today, while working on a webpage, I wanted to implement a feature where a background image is applied to a li element on mouse over, and removed on mouse out. Implemented using JavaScript: if(action == 0) { btn.style.backgroundImage = "url(images/index_nav1_07.jpg)"; btn.style.backgroundRepeat = "repeat-x"; } else { btn.removeAttribute("style"); } I found that this worked for Firefox and Internet Explorer, but the mouse out action did not execute in Chrome. I then discovered that Chrome might not support removeAttribute(), so I added a compatibility fix: ...
In Firefox or IE browsers, when you click on an <a> tag, a dotted outline appears around the tag (as shown in the image), which affects the aesthetics. To solve this issue for IE browsers, add hidefocus="hidefocus" to the <a> tag. For Firefox browsers, the solution is to add the CSS property outline:none