Explaining JavaScript and this to people.
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Marc, that's a lot of stuff to go over man. At lot of these points are mainly due to design concerns and just being old and resistant to change. ;P Forgive me, but I'll have to skim over some of this stuff, but will address some points
Marc Clifton wrote:
- my bias to what I expect. I experience this with Python as well. Anything from differently named functions for string manipulation to the whole abortion called the DOM.
It's an object representation of what's displayed. I'm not sure how it's an abortion. About the only thing I can see with that is old skool compatiblity issues. You can blame Microsoft and Mozilla for that. They didn't give two flips about each other. But those days are gone for the most part. Life is better.
Marc Clifton wrote:
- too many strings.
$("#foo")
Marc, we're professionals man. Come on.
Marc Clifton wrote:
- Standards hell: For example, single quote or double quote:
$("#menu").jqxMenu('close');
Most web languages support both. Can't blame JavaScript for that.
Marc Clifton wrote:
var parentItemText = $($($("#projectTree1").jqxTree('getSelectedItem').parentElement).children("div")[1]).text();
Clearly, you're looking at code written by a 5 year old that doesn't know anything about CSS selectors or jQuery.
Marc Clifton wrote:
Should I do that or not? Performance penalty vs. readability? Is it more readable? Will it confuse someone who has to maintain the code.
Unless you're willing to refactor everything, then yeah that's nifty. The problem here is the design. Back in the olden days, JavaScript was tightly coupled with the DOM. Those days have changed man. I'm not saying it doesn't exist, but it's not nearly has bad as the olden days. Dealing with JScript or VBScript as no different though. It's just the way web dev was for years, and it's not really that much different in concept than XAML and people using ViewModels poorly.
Marc Clifton wrote:
Why do I do this? So I can have a nice function named "getProjectId" that tells me exactly what is going on, without passing in a string and without writing the abortion that looks like this:
Oh Marc, you're having fun with this aren't you? :rolleyes:
Jeremy Falcon wrote:
Clearly, you're looking at code written by a 5 year old that doesn't know anything about CSS selectors or jQuery.
You're off by 50 years. :) And this is exactly why Javascript is so hard to learn. There are no (and no good) resources for how to do things other than SO, CP, and dubious forums by 3rd party vendors. Why? Because who the heck is going to write a book on how to do X when, given the multi-dimensional landscape of web development, describing where X is in this trans-dimensional space is pretty much impossible. Granted, all my examples are related to using jQuery and 3rd party frameworks, but it's impossible to disentangle Javascript from those things when doing web development.
Jeremy Falcon wrote:
but the whole $($($($($('#omg'))))) thing can be avoided.
Beats me how to do it. The content of the tree (a jqxwidget) is programatically generated and I haven't figured out a simpler way of getting the text (not to mention the freaking ID) of the parent for a selected node. One option is to represent the tree as a Javascript structure, this would be simple enough to map ID's in the structure to the DOM that jqwidgets creates. And heaven help me if I have to learn one of the Angular/React/etc/ frameworks that jqwidgets claims to support. More obfuscation on top of nebulous indirection. Yup -- I'm an old fart. ;)
Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
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Just to give you an idea of where the web is headed, here is some ES2015 code...
import React from 'react';
import {Link} from 'react-router';class Layout extends React.Component {
// this requires that the class fields and static properties plug-in is enabled
static propTypes = {
children: PropTypes.object.isRequired
};render() {
// returned JSX must be within parenthesis
return (
// class is a reserved word in JavaScript so we use className insteadheader here and all
{this.props.children} );}
};export default Layout;
Btw, that's not HTML inside the render method. It's just syntactic sugar to look like it. It gets transpiled down to JavaScript. But the only strings you'll see here are in the imports (which isn't much different than C/C++ includes) and the properties that will be spit out to the browser such as "container-fluid". Well, there is the literal there too, but none of the
$($($($('omg'))))stuff. :laugh: Now, I'm not saying everything is perfect with the web. But new-skool web development (especially as WASM gets more popular) is nothing like old-skool web development.Jeremy Falcon
Jeremy Falcon wrote:
ust to give you an idea of where the web is headed,
Could you provide a translation? That is all but unintelligible. ;) I have two reactions. I'm sure I can learn this, and maybe even like it. On the other hand, I really don't want to.
Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
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I think you're conflating JS with web programming. Lets not forget NodeJS baby! 1. While the DOM technically is part of JS, it's only in the context of web programming. 2-7. These were all JQuery, which is not the same as Javascript. I know I speak on behalf of many a JS purist when I say JQuery can die in a hole. 8. Well you already answerd this one. 9. Agreed, frameworks are dumb. But blaming JS for frameworks is like blaming Tim Berners Lee for 4Chan. 10. I don't really have an argument for this one. Obviously I use JS but I've been doing it for so long that *humble brag* I generally don't write code that doesn't work. My IDE tells me when I make a typo though... TBH it seems to me that you have more of a problem with Jquery. And if this is the case, I think we are in furious agreement.
grolarbear wrote:
I think you're conflating JS with web programming.
How can Javascript be separated from web development?
grolarbear wrote:
Lets not forget NodeJS baby!
Yeah. Right. I will never write anything in NodeJS. It's absurd to me to even consider using Javascript for back-end development. Actually it's absurd to me to even consider using Javascript for anything, but there's little choice in that for web development. I do have a choice in server-side stuff. ;)
grolarbear wrote:
These were all JQuery
True. I was realizing that when writing the post. But even if you want jQuery to die in a hole, it's seems so standard (it's pretty hard to find examples that don't use jQuery, particularly examples of 3rd party libs by those very same 3rd parties) and so is again, for web development, entangled.
Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
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Javascript has become a powerful language. With this comes responsibility :~
Press F1 for help or google it. Greetings from Germany
KarstenK wrote:
avascript has become a powerful language.
And Hitler was a powerful dictator.
Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
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Jeremy Falcon wrote:
ust to give you an idea of where the web is headed,
Could you provide a translation? That is all but unintelligible. ;) I have two reactions. I'm sure I can learn this, and maybe even like it. On the other hand, I really don't want to.
Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
Marc Clifton wrote:
On the other hand, I really don't want to.
:laugh: :laugh: :laugh: I know what you mean man. I'm very selective about the tech I learn these days too. There's more to life than just tech ya know.
Marc Clifton wrote:
Could you provide a translation? That is all but unintelligible.
Um, in English that means as the web grows up, it's trying more and more to be like real programming environments. How's that?
Jeremy Falcon
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Jeremy Falcon wrote:
Marc's just old. Don't listen to him.
That's actually what I tell my gf. :)
Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
:-D
Jeremy Falcon
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Jeremy Falcon wrote:
Clearly, you're looking at code written by a 5 year old that doesn't know anything about CSS selectors or jQuery.
You're off by 50 years. :) And this is exactly why Javascript is so hard to learn. There are no (and no good) resources for how to do things other than SO, CP, and dubious forums by 3rd party vendors. Why? Because who the heck is going to write a book on how to do X when, given the multi-dimensional landscape of web development, describing where X is in this trans-dimensional space is pretty much impossible. Granted, all my examples are related to using jQuery and 3rd party frameworks, but it's impossible to disentangle Javascript from those things when doing web development.
Jeremy Falcon wrote:
but the whole $($($($($('#omg'))))) thing can be avoided.
Beats me how to do it. The content of the tree (a jqxwidget) is programatically generated and I haven't figured out a simpler way of getting the text (not to mention the freaking ID) of the parent for a selected node. One option is to represent the tree as a Javascript structure, this would be simple enough to map ID's in the structure to the DOM that jqwidgets creates. And heaven help me if I have to learn one of the Angular/React/etc/ frameworks that jqwidgets claims to support. More obfuscation on top of nebulous indirection. Yup -- I'm an old fart. ;)
Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
Marc Clifton wrote:
You're off by 50 years. :) And this is exactly why Javascript is so hard to learn. There are no (and no good) resources for how to do things other than SO, CP, and dubious forums by 3rd party vendors. Why? Because who the heck is going to write a book on how to do X when, given the multi-dimensional landscape of web development, describing where X is in this trans-dimensional space is pretty much impossible.
You're absolutely right about that. One of the pain points I have with React learning is simply finding good resources on it. And to top it off, once you find one, it's out-of-date. And to top it off even more, it's not exactly places teach you production ready stuff. It's a royal PITA. The web really is a hodgepodge of kiddie playground crap where nobody wants to agree on anything. About the only reason I was able to even start making any sense of all this crap was a couple years back I pestered a coworker of mine for literally like a year asking him tons of questions.
Marc Clifton wrote:
Granted, all my examples are related to using jQuery and 3rd party frameworks, but it's impossible to disentangle Javascript from those things when doing web development.
Yeah totally. It is getting better at least, but the web is slow to migrate to new stuff. Being so popular and all there's a lot of existing crap to change before we make way for the new crap. And of course, by that time the new crap will be out-dated. :-D
Marc Clifton wrote:
The content of the tree (a jqxwidget) is programatically generated and I haven't figured out a simpler way of getting the text (not to mention the freaking ID) of the parent for a selected node.
Having never used that lib, you'd think they'd expose that somehow. Go figure.
Marc Clifton wrote:
And heaven help me if I have to learn one of the Angular/React/etc/ frameworks that jqwidgets claims to support. More obfuscation on top of nebulous indirection.
But... but... React! :-D
Marc Clifton wrote:
Yup -- I'm an old fart.
At least you can laugh about it. You reach an age where it's ok to laugh at stuff. That's called maturity. And I'd say I'm 39 so I understand, but I'm sure you'd call me a youngin'. :~
Jeremy Falcon
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Yup. Don't get me wrong, C is still a favorite language of mine. Always will be, but it's harder to take down the entire OS in JavaScript. :laugh:
Jeremy Falcon
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I tried JSFiddle and it worked. However, when I copied the exact code to a new HTML page, it behaved the same way as it was without "Orange". Here is the complete HTML code:
//copied from JSFiddle var fruit = 'Orange'; window.fruit = 'Apple'; // unlike other languages, in JavaScript we can invoke this in more ways than one function explainThis() { alert(fruit + ' ' + this.fruit); } explainThis(); // shows Orange Apple var stuff = new explainThis(); // shows Orange undefinedTOMZ_KV
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What browser are you running out of curiosity?
Jeremy Falcon
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I tried JSFiddle and it worked. However, when I copied the exact code to a new HTML page, it behaved the same way as it was without "Orange". Here is the complete HTML code:
//copied from JSFiddle var fruit = 'Orange'; window.fruit = 'Apple'; // unlike other languages, in JavaScript we can invoke this in more ways than one function explainThis() { alert(fruit + ' ' + this.fruit); } explainThis(); // shows Orange Apple var stuff = new explainThis(); // shows Orange undefinedTOMZ_KV
Gotcha. It's because stuff ran on JSFiddle is a mock root and not the real root. When using the real root, as in your case, window is the default object, so in the real global scope the first two lines are pretty much the same since window is the default object and so the second assignment overwrites the first. In my original code, it was a fake root so to speak. I probably should've tested it first, but hey where's the fun in that. :) To illustrate...
// this is the real root in the global space
var fruitRoot = 'Banana'; // these two lines do the same thing
window.fruitRoot = 'Pineapple'; // this overwrites the previous linefunction explainThisRoot() { alert(fruitRoot + ' ' + this.fruitRoot); } explainThisRoot(); // shows Pineapple Pineapple var stuffRoot = new explainThisRoot(); // shows Pineapple undefined // this is an IIFE, simply put it's like a namespace (function () { // this can be thought of as a fake root, JSFiddle will do something similar to // constrain the user and prevent them from messing around with the entire page var fruit = 'Orange'; // not in the global space anymore so this isn't window window.fruit = 'Apple'; // unlike other languages, in JavaScript we can invoke this in more ways than one function explainThis() { alert(fruit + ' ' + this.fruit); } explainThis(); // shows Orange Apple var stuff = new explainThis(); // shows Orange undefined })();Jeremy Falcon
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Gotcha. It's because stuff ran on JSFiddle is a mock root and not the real root. When using the real root, as in your case, window is the default object, so in the real global scope the first two lines are pretty much the same since window is the default object and so the second assignment overwrites the first. In my original code, it was a fake root so to speak. I probably should've tested it first, but hey where's the fun in that. :) To illustrate...
// this is the real root in the global space
var fruitRoot = 'Banana'; // these two lines do the same thing
window.fruitRoot = 'Pineapple'; // this overwrites the previous linefunction explainThisRoot() { alert(fruitRoot + ' ' + this.fruitRoot); } explainThisRoot(); // shows Pineapple Pineapple var stuffRoot = new explainThisRoot(); // shows Pineapple undefined // this is an IIFE, simply put it's like a namespace (function () { // this can be thought of as a fake root, JSFiddle will do something similar to // constrain the user and prevent them from messing around with the entire page var fruit = 'Orange'; // not in the global space anymore so this isn't window window.fruit = 'Apple'; // unlike other languages, in JavaScript we can invoke this in more ways than one function explainThis() { alert(fruit + ' ' + this.fruit); } explainThis(); // shows Orange Apple var stuff = new explainThis(); // shows Orange undefined })();Jeremy Falcon
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Marc Clifton wrote:
You're off by 50 years. :) And this is exactly why Javascript is so hard to learn. There are no (and no good) resources for how to do things other than SO, CP, and dubious forums by 3rd party vendors. Why? Because who the heck is going to write a book on how to do X when, given the multi-dimensional landscape of web development, describing where X is in this trans-dimensional space is pretty much impossible.
You're absolutely right about that. One of the pain points I have with React learning is simply finding good resources on it. And to top it off, once you find one, it's out-of-date. And to top it off even more, it's not exactly places teach you production ready stuff. It's a royal PITA. The web really is a hodgepodge of kiddie playground crap where nobody wants to agree on anything. About the only reason I was able to even start making any sense of all this crap was a couple years back I pestered a coworker of mine for literally like a year asking him tons of questions.
Marc Clifton wrote:
Granted, all my examples are related to using jQuery and 3rd party frameworks, but it's impossible to disentangle Javascript from those things when doing web development.
Yeah totally. It is getting better at least, but the web is slow to migrate to new stuff. Being so popular and all there's a lot of existing crap to change before we make way for the new crap. And of course, by that time the new crap will be out-dated. :-D
Marc Clifton wrote:
The content of the tree (a jqxwidget) is programatically generated and I haven't figured out a simpler way of getting the text (not to mention the freaking ID) of the parent for a selected node.
Having never used that lib, you'd think they'd expose that somehow. Go figure.
Marc Clifton wrote:
And heaven help me if I have to learn one of the Angular/React/etc/ frameworks that jqwidgets claims to support. More obfuscation on top of nebulous indirection.
But... but... React! :-D
Marc Clifton wrote:
Yup -- I'm an old fart.
At least you can laugh about it. You reach an age where it's ok to laugh at stuff. That's called maturity. And I'd say I'm 39 so I understand, but I'm sure you'd call me a youngin'. :~
Jeremy Falcon
Jeremy Falcon wrote:
You reach an age where it's ok to laugh at stuff.
Yeah, works well with one's partner too. ;) At the end of the day, I end up treating these technologies like everything else, even C#/.NET: 1) Figure out how to do stuff the hard way 2) Look at how to make it easier and learn from others 3) Create a toolbox that mitigates some of the pain points 4) Liberally sprinkle code with
// TODO: Kludge!and// TODO: There has to be a better way!:)Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
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Jeremy Falcon wrote:
You reach an age where it's ok to laugh at stuff.
Yeah, works well with one's partner too. ;) At the end of the day, I end up treating these technologies like everything else, even C#/.NET: 1) Figure out how to do stuff the hard way 2) Look at how to make it easier and learn from others 3) Create a toolbox that mitigates some of the pain points 4) Liberally sprinkle code with
// TODO: Kludge!and// TODO: There has to be a better way!:)Latest Article - Class-less Coding - Minimalist C# and Why F# and Function Programming Has Some Advantages Learning to code with python is like learning to swim with those little arm floaties. It gives you undeserved confidence and will eventually drown you. - DangerBunny Artificial intelligence is the only remedy for natural stupidity. - CDP1802
Marc Clifton wrote:
Liberally sprinkle code with
// TODO: Kludge!and// TODO: There has to be a better way!I do the same thing too. :laugh:
Jeremy Falcon
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I am currently writing a road traffic simulator in javascript and both at work and in this project the one thing that makes javascript difficult is scope. Basically the manner in which scope is implemented javascript makes it that much more difficult than it needs to be. That said I have found that programming in javascritpt has made me a better developer because there are so many ways you can do things badly in javascript.
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
Personally I find any issues that arise from scope can be resolved by the immutability of objects. I have no idea if this is good practice, but passing object references around or just having a global or high-up object with important stuff is how I like to do it.