@davidjcastner I think I asked this exact question before, but I find myself stuck on it again: how can I take the
string stored inside a variable, and make it the var name (e.g.var ‘this’ = new HappyFace) for a new instance of a class?
var happy = “ImSoHappy”;
var “ImSoHappy” = new HappyFace();
something like that
obviously without the “” in the
var name, it’s just there to point out that it came from the string inside happy
that functionality doesn't exist, you could store it in an object though and use that
var App = {};
var happy = 'ImSoHappy';
App[happy] = new HappyFace();
how would I log the instance then?
you can then even access it like so:
App.ImSoHappy instanceof HappyFace; // truebut the correct way to access a variable that you define like this is:
App[happy]@SimplyPhy what do you mean by
how would I log the instance then?
except, a version that works
like how can i access that instance? App.ImSoHappy doesn’t seem to do it
oh i didn’t define the constructor function, i think the issue is
muhaha
it works :D
interesting solution, probably simple but i love it :D
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thanks @davidjcastner
simplyphy sends brownie points to @davidjcastner :sparkles: :thumbsup: :sparkles:
:cookie: 354 | @davidjcastner |http://www.freecodecamp.com/davidjcastner
no problem make sure to use
App[happy] syntax and NOT App.ImSoHappy. It's clearer how you are defining the variable name, just wanted to point out that you access it like that
that’s really awesome, i’m going to use that to store form data into localStorage where the course[i].section[j].segment[k] === the localStorage object name :D
oh wait, I thought
App[happy] == App.ImSoHappy ?
yes they are technically equivalent, but it's considered bad coding practice to use the latter
since if someone goes to look at your code, including yourself later on, and that person wanted to see where
App.ImSoHappy is defined they wouldn't be able to find it
I was hoping to do away with object[property] syntax altogether aside from being able to read it, but yeah it’s definitely better in this situation...
now if you define your app like this:
// way one
var HappyFace = function() {};
var App = {
ImSoHappy: new HappyFace()
};
// semantic way to access the variable this way
console.log(App.ImSoHappy instanceof HappyFace); //true
// way two
var App = {};
var happy = 'ImSoHappy';
App[happy] = new HappyFace();
// semantic way to access the variable this way
console.log(App[happy] instanceof HappyFace); //true
yes the reason for accessing it using the
object[property] syntax is because the property name itself is a variable
hope that makes sense
yup, i’m still grappling with it somewhat, but i’m digesting it
coping with the fact that
obj[prop] !== obj.prop in all situations
namely, when
prop === defined; // true, i guess
var HappyFace = function() {};
var App = {};
var happy = 'ImSoHappy.hello';
App[happy] = new HappyFace();
// this explains a case where the obj[prop] !== obj.prop
console.log(App[happy] instanceof HappyFace); //true
console.log(App[happy]); // {}
console.log(App.ImSoHappy.hello); // TypeError: Cannot read property 'hello' of undefined
the answer to your question @ringmaster is right above where you asked it
a more complete answer to your question is contained within this most conversation
Ok. Was worried my whole world was turning upside-down there for a minute. Please carry on.
haha i was worried a tad too, though my concerns were better warranted, given my previous worldview
@davidjcastner has a way of ruining my life :P
hope that last example clears up why to use one syntax over the other
thanks again @davidjcastner
simplyphy sends brownie points to @davidjcastner :sparkles: :thumbsup: :sparkles:
:warning: simplyphy already gave davidjcastner points
don't worry about the montbot
I'm on a diet don't about sending me more cookies
I’m unsure why, if you initially used
happy=‘foo’; App[happy] = bar; you would ever try to use App.foo directly, anyway. That part doesn’t make sense to me. ¯\(ツ)/¯
because i’m an inexperienced programmer who decided he would exclusively use dot notation for object property access, prior to this revelation
speaking of leveling up, I discovered codefights.com two nights ago..neat for me :D
also, I get $1000 if anyone i refer beats a company sponsored bot, so let me know if you want to give it a go and i’ll split the winnings with you :D
oh wait, you have to beat a company’s bot, apply to a position at that company, and get accepted…then i get $1000 xD
I was going to say, “Give me a link,” but, yeah… don’t need a job. :)
you basically are given programming challenges of varying difficulty (sometimes a bug, sometimes missing piece of program, something solve challenge, etc), and you compete with either a bot or a person to produce a program that passed all of the visible (and hidden) tests that are run against your program to see how comprehensively you solved the challenge
each “fight” involves 3 challenges, and you get points based on how many tests your program successfully passes
if you and the bot/person ty in points, the winner is decided by who did it faster, overall
last night the one i did took 1.5 mins for the first vhallenge, 55 mins for the second challenge (because i’m an idiot and had to think through how to build a factorial calculator), and the third took 1.5 mins
the night before, i had an easy one that took like 5-10 mins total, and after that i did one where i solved the first challenge really fast, and solved the second one in about 15 minutes, but one of the damn “hidden” tests (they show you some tests they run against your program, and you can create as many custom tests as you want, but they never show you the hidden tests) kept failing
i still have no idea why that one damn test kept failing, i spent like 2 hours trying every combination possible, and i couldn’t pass that one damn test. I got to the point where i honestly thought it was bugged
it just occurred to me that the bot i was facing with that one challenge was the asana company bot xD
i thought it was just a default bot (there are 6 standard bots, presumably each more challenging than the prior)
hmm I'll probably give it a go when I get some free time
the challenges are actually usually interesting, at least in my experience thus far
plus we can challenge eachother, and you can create your own bot, and create teams, etc :smiling_imp:
https://codefights.com/signup/2GPCrETsJ7cJRCYaH/main that’s my custom invite URL if @all want it
https://codefights.com/tournaments/pM6uRn4H3osCbiGzq < this 10 min tournament begins basically now, if you want to try it :D
Given a rectangular matrix of integers and integers n and m, we are looking for the submatrix of size n × m that has the maximal sum among all submatrices of the given size.
Example
For
matrix = [[1, 12, 11, 10],
[4, 3, 2, 9],
[5, 6, 7, 8]]
n = 2 and
m = 1, the output should be
maxSubmatrixSum(matrix, n, m) = 19.
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Thanks @ringmaster and @davidjcastner for your advice about the freelance job. I was able to bill an amount that worked for both me and the company. I completed the project today: http://codepen.io/kevincauto/pen/kXRmoz