转载：SQL Window Functions: The Ultimate Guide - Database Star What is an SQL window function? Why should you know about it? And what can it help you with? You may have heard of SQL window functions before, or they may be completely new to you. Learn all about them in this guide. # What is a Window...

# Median Define 统计学上，中位数（Median），又称中央值、中值，是一个样本、种群或概率分布中之一个数值，其可将数值集合划分为数量相等的上下两部分。对于有限的数集，可以通过把所有观察值高低排序后找出正中间的一个作为中位数。如果观察值有偶数个，则中位数不唯一，通常取最中间的两个数值的平均数作为中位数。 一个数集中最多有一半的数值小于中位数，也最多有一半的数值大于中位数。如果大于和小于中位数的数值个数均少于一半，那么数集中必有若干值等同于中位数。 # Data Set 123456789101112create table movie_ratings ( rating...

转载：How to Get the Screen, Window, and Web Page Sizes in JavaScript To detect whether the browser window is in landscape or portrait mode, you can compare the browser window’s width and height. But from my experience it’s easy to get confused in the bunch of sizes: screen, window, web page...

转载： 7 Simple but Tricky JavaScript Interview Questions My top stressing things in software development are: The coding interview A toxic manager or teammate Not JavaScript, this , CSS, Internet Explorer, but the 2 above. If you’re qualifying as Senior Developer whose job involves JavaScript,...

转载：JavaScript Variables Lifecycle: Why let Is Not Hoisted Hoisting is the process of virtually moving the variable or function definition to the beginning of the scope, usually for variable statement var and function declaration function fun() {...} . When let (and also const and...

转载: Detailed Overview of Well-known Symbols Symbol is a new primitive type available from ECMAScript 2015, which allow to create unique identifiers let uniqueKey = Symbol('SymbolName') . You may use symbols as keys of properties in objects. A list of symbols that JavaScript treats specially...

转载: JavaScript Addition Operator in Details # Introduction JavaScript is an awesome language. I like it because of the flexibility: just do the things in a way you like: change the variable type, add methods or properties to object on the fly, use operators on different variable types and much...

转载：The Legend of JavaScript Equality Operator Sometimes when I’m writing Javascript I want to throw up my hands and say ‘this is bullshit!’ During everyday JavaScript coding, it may be hard to see how the equality operator works. Especially when the operands have different types. Time to time this...

转载：What’s the Difference between DOM Node and Element? The Document Object Model (DOM) is an interface that treats HTML or XML document as a tree structure, where each node is an object of the document. DOM also provides a set of methods to query the tree, alter the structure, style. DOM also uses...