String breaking & duplicate check

Hello. So i am writing a program that requires me to check if there are any repeating characters in string (error). Also, i need to know a way how to break string into array of characters. Anyone can help?

To break up a string you can do:

usernameLetters = {} --# Stores the individual letter for the broken up name
function breakString(username) --# This Breaks up the string
	    for i = 1, username:len() do --# username is a string value
			    table.insert(usernameLetters, username:sub(i, i))
	    end
end

Yep, you have to use string.sub and iterate through all the characters of the string.

local array = {}
local text = "Some stuff here!"
for i=1,#text do --  the iteration
    array[#array+1] = text:sub(i,i) -- take the character at the position
end

Hope I helped.

Damn it, ninja'd

Creator, on 11 November 2015 - 10:56 AM said:

Yep, you have to use string.sub and iterate through all the characters of the string.

local array = {}
local text = "Some stuff here!"
for i=1,#text do --  the iteration
	array[#array+1] = text:sub(i,i) -- take the character at the position
end

Hope I helped.

Damn it, ninja'd

Thanks. But i have second question. How to now check for duplicates in received array?

Well again, you should iterate (What a coincidence I am in IT class and learning about iterations in C++)
If you want to eliminate duplicates:

array -- the array from the prev example
local chars = {}
local newArray = {}
for i=1,#array do
    local current = array[i]
    if not chars[current] then
	   char[current] = true
	   newArray[#newArray+1] = current
    end
end

Creator, on 11 November 2015 - 11:19 AM said:

Well again, you should iterate (What a coincidence I am in IT class and learning about iterations in C++)
If you want to eliminate duplicates:

array -- the array from the prev example
local chars = {}
local newArray = {}
for i=1,#array do
	local current = array[i]
	if not chars[current] then
	   char[current] = true
	   newArray[#newArray+1] = current
	end
end

And newArray will contain all filtered characters?

Yes it will

Just for completeness, here is Another way to split a string:

local array = {}
local str = "YourStringHere"
for char in str:gmatch(".") do
  table.insert(array,char)
end