var - A variable is a stored set of information, it can be a boolean, null, undefined, a string, a float/integer, an array, an object, or more.

function - A function is made up of two parts, the function itself that runs any code inside of it, and the function call.

document - The document is an object that is essentially a collection of everything on your web page.

if / else if / else - An if statement creates a situation where if the set parameters are met, it will execute some code.

for - A for loop is a section of code that will run multiple times until the set parameters are met.

this - This is a special keyword which essentially references whatever scope you are currently working in.

class - A class is a type of object that can be cloned to create duplicates of itself, the class object in itself being a clone of the original class.

new - New is a constructor that creates a copy of a JS class, which is essentially a pre-made sort of object.

An if statement, as mentioned earlier, is a code segment that will run, top to bottom only if the provided parameter you set is valid (true).

When using && and || it reads left to right, so be sure that for && you have things in the proper order.

You always start with an if, followed by as many else if as you want or simply an else with no parameters.

if (eggs >= 12) {
    bakeCake();

} else if (eggs == 6) {
    makeOmelette();

} else if (eggs == 1 && people !> 2) {
    makeFriedEgg();

} else {
    console.log("Buy Eggs")
}

                    

A for loop is a section of code that loops a specified amount of times until it’s set condition is no longer valid.

Be careful when using a for loop, if your conditions can never be met it will loop infinitely.

The for loop has a cousin that serves a relatively similar purpose, the while loop, which will continue until the set condition is false. Be very careful with it, you have to create the iteration condition inside of it and will also loop infinitely if used wrong. while( i > 5 )

The for loop also has a close sibling, the forEach function, that serves to loop through all of the values inside of an array. It will run your code with the variable name you set for the values and apply the code to all of them in order. You can call the values whatever you want, and if it is an array filled with objects can loop through specific keys. array.forEach(function(value){console.log(value)})

for ( var i = 0; i < 365; i++ ){
    console.log(“WATCH ME COUNT” + i);
};

                    

Bracket Types

( ) : functions & conditions
Regular round brackets are only used when it comes to functions and conditions when using for loops, while, loops, if statements and more. You use them to create functions with parameters or to call functions.

{ } : start & end/thing to be executed
Squiggly brackets/Braces are used to show the start and end of a set of code to be executed, usually after the if statement, function declaration, or for loop. They are also used with objects showing the start and end of an object.

[ ] : array
Square brackets show the start & end of arrays, they can be used to reference specific spots in arrays and in objects as well! object[key] === object.key

Additional Syntax

.
As you have probably seen already the . is used quite a bit in JS, its purpose is mainly to access properties inside of something, or to apply a function call on something. Which does contain that function in it.

Be sure to check the following:

Spelling of Ids and Classes is consistent and correct.

When using getElementsByClassName, remember it returns an array so use getElementsByClassName[elementYouWant].

Make sure your > and < are facing the right direction.

Make sure your brackets are closing properly; sometimes formatting or beautifying your code helps.

Make sure the stuff you're referencing is within the function or global (see scope).

Check for loops and if statements to make sure they have the right condition.

Look for missing semicolons ; , apostrophes ' ' " " , squiggly brackets { } , or regular brackets ( ) , or commas ,