How does this type of 'if then end' statement work? [closed]

Using if looks like this (when not using else or elseif):

if ex then
    -- body
    -- body
end

Where ex is any expression. if cares only whether or not the evaluation of the expression is truthy or falsy (most values are truthy. nil and false are falsy)

It does not care how it is written (just like expressions anywhere else)

What do I mean by "expression"?

Literals are expressions:

• An expression can be something like a number, e.g., 5 or -3.9.
• An expression can be other literals like "cat" or true or nil

Variables are expressions:

• A simple variable is an expression (apple)
• ROBLOX or Lua objects like {1,2,3} or table or game.Workspace or BrickColor.new("Bright blue")
• Properties are expressions like Part.Parent or Part.Transparency

Operations on expressions are expressions (making new compound expressions)

• Using math on expressions makes a new expression

• • 5 + 4 is an expression
• • Vector3.new(3,4,2) + Vector3.new(1,2,0) is an expression
• • 5 * amt is an expression

• Function calls are expressions

• • math.cos( angle ) is an expression
• • math.sqrt( math.pow(5, 4) ) is an expression

• Other operators, including logical operators and comparison operators also form compound expressions

• • a == b is an expression
• • a < b is an expression
• • a and b is an expression

So, what it "looks" like doesn't really matter. It just needs to be an expression.

Since that expression will essentially be either truthy or falsey, it is frequent to use ==, <=, <, >= and > to compare numbers, since these produce true and false.

It's also common to use and which requires that both the thing to the left and right of it are truthy; or or which requires at least one of the thing to the left and right of it is truthy; or not which inverts the truthiness of a particular value (not true is false and vice versa)

You can print any expression.

So you can easily play around with different structures for conditions.

apple = "cat"
print( apple == "cat" ) -- true
print( apple == "dog" ) -- false

print( (apple == "cat") and (5 < 3) ) -- false
print( (apple == "cat") and (5 > 3) ) -- true
print( (apple == "dog") and (5 > 3) ) -- false
print( not apple ) -- false
print( (not apple) or (5 > 3) ) -- true

Programming languages are usually extremely consistent.

If you can do something in one place, you can probably do it anywhere else (unless there's a good reason you can't)

There are lots of unorthodox things that can be done:

game.Workspace.Parent.Workspace.Parent.Workspace.BlueTaslem:BreakJoints()
-- Same as
game.Workspace.BlueTaslem:BreakJoints()