wilm42/scope

## scope
Q1: What is scope?
'Scope' refers to the places that a variable can be called on in javascript. A variable with 'local scope' is one that
is defined within a specific function, and can only be used within that function. If it is used elsewhere without being
redefined, you'll get an uncaught ref error. A variable with 'global scope' is one that is defined outside of a function.
variables with global scope can be called on anywhere in your code, even between files.

Q2: Why are global variables avoided?
Global variables are to be avoided because they cause a lot of bugs. The reason they cause a lot of bugs is because you can
accidentally mutate them in a function, and then when you call on them again later, the mutated data held by the variable
is not what you were expecting. By keeping your variables local, you're creating a variable and then directly working with it,
not mutating something that you may have written further up in your code or even in another file.

Q3: Explain JavaScript's strict mode
Another way (beside just typing it outside of a function) to create a global variable is by omitting the var keyword, even
inside of a function. JavaScript's strict mode does not allow this to happen, if you name a variable without the var keyword
and then reference it, you will get an uncaught ref error. this forces you to use the var keyword.

Q4: What are side effects, and what is a pure function?
If, in a function, you set a value to a variable that is not contained within that fucntion, you've created a side effect.
If you do this by accident, you've created an indeterminate function. A function is pure when it is both Determinite (i.e.
not indeterminate) and free of side effects. Pure functions should be the standard unless you specifically need one that
is not pure.

Q5: Explain variable hoisting in JavaScript.
When a js interpreter reads over your code, it does so in two passes - on the first pass, it will look for any variable
declarations and set aside space for them in it's memory. It does not, however, set a value to your variables until the
second pass - instead, it defaults to undefined. the term 'hoisting' refers to how the interpreter seems to 'hoist'
your variable declarations above anything else in a block. by this property, you can reference varibles that you haven't yet
declared in your function, though their value will be undefined.
	Q1: What is scope?
	'Scope' refers to the places that a variable can be called on in javascript. A variable with 'local scope' is one that
	is defined within a specific function, and can only be used within that function. If it is used elsewhere without being
	redefined, you'll get an uncaught ref error. A variable with 'global scope' is one that is defined outside of a function.
	variables with global scope can be called on anywhere in your code, even between files.

	Q2: Why are global variables avoided?
	Global variables are to be avoided because they cause a lot of bugs. The reason they cause a lot of bugs is because you can
	accidentally mutate them in a function, and then when you call on them again later, the mutated data held by the variable
	is not what you were expecting. By keeping your variables local, you're creating a variable and then directly working with it,
	not mutating something that you may have written further up in your code or even in another file.

	Q3: Explain JavaScript's strict mode
	Another way (beside just typing it outside of a function) to create a global variable is by omitting the var keyword, even
	inside of a function. JavaScript's strict mode does not allow this to happen, if you name a variable without the var keyword
	and then reference it, you will get an uncaught ref error. this forces you to use the var keyword.

	Q4: What are side effects, and what is a pure function?
	If, in a function, you set a value to a variable that is not contained within that fucntion, you've created a side effect.
	If you do this by accident, you've created an indeterminate function. A function is pure when it is both Determinite (i.e.
	not indeterminate) and free of side effects. Pure functions should be the standard unless you specifically need one that
	is not pure.

	Q5: Explain variable hoisting in JavaScript.
	When a js interpreter reads over your code, it does so in two passes - on the first pass, it will look for any variable
	declarations and set aside space for them in it's memory. It does not, however, set a value to your variables until the
	second pass - instead, it defaults to undefined. the term 'hoisting' refers to how the interpreter seems to 'hoist'
	your variable declarations above anything else in a block. by this property, you can reference varibles that you haven't yet
	declared in your function, though their value will be undefined.