CODEWITHSUNDEEP
stringluaint
Randy Lust
Randy Lust

Reputation: 11

I am trying to convert a string in decimal format to a number in lua

I have 2 integer variables that I want to covert to a decimal integer. The result should be like this:

a = 10 
b = 12
c = 10.12

I can convert them with concatenate to a string decimal but then I cannot use math functions on the result. I have tried to use tonumber() on the string but I got a nil value.

Upvotes: 1

Views: 1556

Answers (1)

Rochet2
Rochet2

Reputation: 1156

I assume in the beginning a and b are integers and you wanted to join them so that a is the integer part of the resulting number and b is the decimal part - the part after the comma or dot in a double or float.

This is the string concat solution you suggested which works fine for me

a = 10
b = 12

c = tonumber(a..'.'..b)
print(c) -- prints 10.12

Here we are using math to calculate amount to divide b to get it as the correct decimal and then we add it to a. The code for determining the power of 10 was found here: How can I count the digits in an integer without a string cast?

a = 10
b = 12

c = a + b / math.pow(10, b == 0 and 1 or math.floor(math.log(math.abs(b), 10))+1)
print(c) -- prints 10.12

Upvotes: 1

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