"Adding" a number to an variable

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qrux
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"Adding" a number to an variable

Post by qrux » Wed Apr 25, 2012 11:13 pm

Hello!
I have a problem;

Let's say i have an variable of the number 250. I want to modify this number by adding digits after it. Like, if i press my "1" button i have created, i want the variable to be 2501 (not 251).

If i do variable+1, it will (of course) just become 251, which is not what i want.

Thanks!

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tentus
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Re: "Adding" a number to an variable

Post by tentus » Wed Apr 25, 2012 11:54 pm

You mean like this?

Code: Select all

function love.load()
	x = 0
end
function love.draw()
  love.graphics.print(x, 5, 5) 
end
function love.keyreleased(key)
	if tonumber(key) then
		x = (x * 10) + tonumber(key)
	end
end
Kurosuke needs beta testers

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kraftman
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Re: "Adding" a number to an variable

Post by kraftman » Wed Apr 25, 2012 11:57 pm

qrux wrote:Hello!
I have a problem;

Let's say i have an variable of the number 250. I want to modify this number by adding digits after it. Like, if i press my "1" button i have created, i want the variable to be 2501 (not 251).

If i do variable+1, it will (of course) just become 251, which is not what i want.

Thanks!
if you want to keep it as a number: newnumber = tonumber(oldnumber..1)

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Ensayia
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Re: "Adding" a number to an variable

Post by Ensayia » Wed Apr 25, 2012 11:58 pm

I suppose you could cast the variable to a string, then add the '1' as a string and cast it back to a number.

Code: Select all

somevar = 250
somevar = tonumber(tostring(somevar).."1")
That's untested, but give it a try, it might work. There's likely a more elegant way of doing this.

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TechnoCat
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Re: "Adding" a number to an variable

Post by TechnoCat » Thu Apr 26, 2012 2:32 am

Ensayia wrote:I suppose you could cast the variable to a string, then add the '1' as a string and cast it back to a number.

Code: Select all

somevar = 250
somevar = tonumber(tostring(somevar).."1")
That's untested, but give it a try, it might work. There's likely a more elegant way of doing this.
Here is the more elegant way: http://codepad.org/T3PQWp4Y

Code: Select all

test = 12
test = test..3
print(test)
print(test + 1)
EDIT: I guess it is technically a string now, but nothing a tonumber() can't fix if you absolutely need it to be a number.
Last edited by TechnoCat on Thu Apr 26, 2012 4:22 am, edited 2 times in total.

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Ensayia
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Re: "Adding" a number to an variable

Post by Ensayia » Thu Apr 26, 2012 2:53 am

I was not aware you could concat a number on like that. You learn something every day. :ultraglee:

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Roland_Yonaba
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Re: "Adding" a number to an variable

Post by Roland_Yonaba » Thu Apr 26, 2012 11:26 am

Ensayia wrote:I was not aware you could concat a number on like that. You learn something every day. :ultraglee:
http://www.lua.org/pil/3.4.html

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qrux
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Re: "Adding" a number to an variable

Post by qrux » Thu Apr 26, 2012 8:04 pm

Got it working. Thank you :)

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Robin
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Re: "Adding" a number to an variable

Post by Robin » Thu Apr 26, 2012 8:54 pm

Roland_Yonaba wrote:
Ensayia wrote:I was not aware you could concat a number on like that. You learn something every day. :ultraglee:
http://www.lua.org/pil/3.4.html
Ah, automatic coercion. The cause of --- and solution to --- all the world's problems.
Help us help you: attach a .love.

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Ensayia
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Re: "Adding" a number to an variable

Post by Ensayia » Thu Apr 26, 2012 9:14 pm

Lua lets you do quite a few more things with easy shortcuts than any other language. I really feel spoiled by it, it would probably be hard for me to start learning another language. There's no way C, C++, Java, etc would allow you to do something that elegant...

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