Looking at all the information out there on JSlint (eg. here or here), the discussion goes something like this Always use strict mode since it catches many more errors. All you have to do is put ‘use strict’ at the top of your code. That’s it! Couldn’t be easier… Except when JSlint complains and tells you to put it in
Tag: scope
Variable Hoisting in Javascript List of Adders
I have learned the basics of variable hoisting in JavaScript, and am now trying to enhance it by doing some exercises. I’ve come across this piece of code: This code first creates an array of functions from a given list. Each function adds the same passed number (in this case 100) to a particular value of the list and prints
How to access an array from the scope of a function
I’m trying to add an element into an array with the push() method but apparently, I can’t access that array from the scope of my function. Here’s a summary of my architecture : I know for sure that the problem come from the array. When executing the code, I have an error telling me that push isn’t a propriety of
A question regarding jQuery hover(), setInterval scope, and The “this” Problem —
UPDATE — from CertainPerformance: This helped with the scope question; but now I have a follow up – Each image at position i needs to be iterating over a separate index, index which determines the current src of the image at position i. The starting index for each image’s setInterval loop should be its position and then index++ each loop.
Inner function does not return changes to variable assigned in outer function
I am attempting to modify the masterCounter variable within the timeKeyAdditionCheck function. Within the timeKeyAdditionCheck function, I successfully assign a value to masterCounter, but this change is not reflected within the scope of getEventsWithTime. When timeKeyAdditionCheck is complete, the value of masterCounter returns to null. What changes do I need to make with timeKeyAdditionCheck function? Answer The reason I wasn’t
Declare global constants in function javascript on DOMContentLoaded
Is there any way to declare constants when the DOMContentLoaded event triggers, that are accessible outside? Answer If the question is: “Is there any way to declare a constant variable without a value, and assign one to it later?”, then the answer is no. Think of it again: after the declaration, a constant variable’s value must always be the same;
Why is the variable `closed` being logged as `false`, if I define it globally as `0`?
I know this must be really basic stuff but I don’t understand how the scope is working. I want the closed variable be known in the entire JavaScript file. I have something like that (in jQuery): But closed is getting logged as false. I tried many things with load and onload functions, but I failed. Answer Use let instead of
What is the purpose of the script scope?
When inspecting scopes of a function in the DevTools console I noticed a “script” scope. After a bit of research it seems to be created for let and const variables. Scopes of a function in a script without const or let variables: Scopes of a function in a script with a let variable: Yet the following prints 1 in the
Define a global variable in a JavaScript function
Is it possible to define a global variable in a JavaScript function? I want use the trailimage variable (declared in the makeObj function) in other functions. Answer As the others have said, you can use var at global scope (outside of all functions and modules) to declare a global variable: (Note that that’s only true at global scope. If that
Preventing auto-creation of global variables in Javascript
I just spent some time debugging a problem that boiled down to forgetting to use the var keyword in front of a new variable identifier, so Javascript was automatically creating that variable in the global scope. Is there any way to prevent this, or change the default behavior, without using a validator like JSLint? Running a validator in between writing