Strings to numbers

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Techron
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Strings to numbers

Post by Techron » Sat Mar 07, 2015 12:48 am

Hello!
I have this issue when I am trying to load a save file. It gives me an error saying that I cannot compare a string to a number, and I obviously know that's the problem. Is there any way I can convert a string to a number, or possibly declaring the variable a number in the save? Sorry if that sounded confusing, this is my first forum post.

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BluBillz
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Re: Strings to numbers

Post by BluBillz » Sat Mar 07, 2015 1:22 am

Try adding # before the variable. If it was in a table i believe it should work out like that.

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arampl
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Re: Strings to numbers

Post by arampl » Sat Mar 07, 2015 4:04 am

I thought tonumber(a) serves this purpose, and # is for element count in the table. Am I wrong?

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ivan
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Re: Strings to numbers

Post by ivan » Sat Mar 07, 2015 4:58 am

You can use "tonumber".

Code: Select all

assert(type(s) == "string", "input must be a string")
n = tonumber(s)
assert(type(n) == "number", "conversion failed!")
Should work with decimal numbers or hex numbers.
Returns nil if it fails to convert the number.

Turns out that "#s" for strings is used to get the number of bytes, similar to "string.len":

Code: Select all

a = "012345"
assert(#a == 6, "string is not 6 bytes long!")
The length operator is denoted by the unary operator #. The length of a string is its number of bytes (that is, the usual meaning of string length when each character is one byte).
Note that for UTF8 strings, the number of bytes may not equal the number of characters.

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