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  Resolve stylesheet_link_tag fails to work in Ruby on Rails

When developing Ruby On Rails application, developers sometimes will see an unexpected behavior where the application cannot be loaded due to "TypeError: Object doesn't support this property or method" when invoking stylesheet_link_tag. The symptom looks like  And the Rails log will show something similar to below The error occurs because there is some problem finding the correct assets which are located in app/assets. To resolve the issue, you can following below steps. Add gem 'coffee-...

   RUBY ON RAILS,STYLESHEET_LINK_TAG,JAVASCRIPT_INCLUDE_TAG,TYPEERROR     2016-10-14 03:59:11

  Five-minute Multimethods in Python

So what are multimethods? I'll give you my own definition, as I've come to understand them: a function that has multiple versions, distinguished by the type of the arguments. (Some people go beyond this and also allow versions distinguished by the value of the arguments; I'm not addressing this here.) As a very simple example, let's suppose we have a function that we want to define for two ints, two floats, or two strings. Of course, we could define it as follows: def foo(a, b): if...

   Python,Multimethod,Argument list,Version,Overloadding     2011-12-07 08:41:03

  Can a == true && a == false be true in JavaScript?

JavaScript is a weak typed language and it has a loose comparison feature where two objects/values of different type can be compared using == operator. This provides developers great flexibility and confusion at the same time.  Before understanding how == works in JavaScript, can you first answer the question in the post title? Can a == true && a == false be true in JavaScript? Normally, we would think that this expression will always return false since a can be either true or ...

   JAVASCRIPT,COMPARISON,INTERVIEW QUESTION,==     2018-03-25 03:39:43

  Let's talk about JSON.stringify()

JSON has been used in lots of places to exchange data among different services/systems. Nowadays all mainstream programming languages have built-in library support of JSON data parse and stringify. In this post, let's talk about JSON.stringify() in JavaScript. Let's first take a small example of Object conversion handling. There is a requirement to convert below object const todayILearn = { _id: 1, content: '今天学习 JSON.stringify()，我很开心！', ...

   JAVASCIPT,JSON,JSON.STRINGIFY     2020-02-22 04:25:08

  An Object is not a Hash

Following my article A String is not an Error, I want to bring attention to an issue that similarly applies to JavaScript in general, but has special relevance in the Node.JS environment. The problem boils down to the usage of {} as a data-structure where the keys are supplied by untrusted user input, and the mechanisms that are normally used to assert whether a key exists. Consider the example of a simple blog created with Express. We decide to store blog posts in memory in a {}, indexed ...

   Object,Hash,Node.js,JavaScript     2012-01-19 10:16:10

  Unfortunate Python

Python is a wonderful language, but some parts should really have bright WARNING signs all over them. There are features that just can't be used safely and others are that are useful but people tend to use in the wrong ways. This is a rough transcript of the talk I gave at my local Python group on November 15, with some of the audience feed back mixed in. Most of this came from hanging around the Python IRC channel, something I highly recommend. [update 2011-12-19: improved "array" cr...

   Python,Defects,Deprecated methods,Warning     2011-12-20 08:27:36

  JavaScript's Two Zeros

JavaScript has two zeros: -0 and +0. This post explains why that is and where it matters in practice. The signed zero Numbers always need to be encoded to be stored digitally. Why do some encodings have two zeros? As an example, let’s look at encoding integers as 4-digit binary numbers, via the sign-and-magnitude method. There, one uses one bit for the sign (0 if positive, 1 if negative) and the remaining bits for the magnitude (absolute value). Therefore, -2 and +2 are encoded as f...

   JavaScript,zeros     2012-03-24 05:21:49

  A re-introduction to JavaScript

Introduction Why a re-introduction? Because JavaScript has a reasonable claim to being the world's most misunderstood programming language. While often derided as a toy, beneath its deceptive simplicity lie some powerful language features. 2005 saw the launch of a number of high-profile JavaScript applications, showing that deeper knowledge of this technology is an important skill for any web developer. It's useful to start with an idea of the language's history. JavaScript was created in 1...

   JavaScript,Types,Array,Re-introduction,OOP     2012-02-09 05:38:08

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