difference between list and set in java code example

Example 1: difference between java and javascript

java is virtualised and compiled while javascript isn't.
javascript and java aren't that similar apart from beign 
both OOP.

Example 2: List vs Set

List > Ordered and Indexed Collection, May contain duplicates
Set > Collection of Unique values, not ordered, no indexing

Example 3: Ruby difference between for and .each

# They are both similar in function, however the for loop will retain a variable.
# FOR Example:
nums = [1,2,3]

for n in nums
	puts n
end
=> 1 2 3

# If you ask what is n, n outputs the last assignment from the function.
n => 3

# EACH Example:

nums.each do |i|
	puts i
end
=> 1 2 3

# If you ask what is i.
i => NameError (undefined local variable or method `i' for main:Object)