# Programming Fundamentals/Arrays/Ruby

## arrays.rb

```# This program uses arrays to display temperature conversion tables
# and temperature as an array subscript to find a given conversion.
#
# References:
#     https://www.mathsisfun.com/temperature-conversion.html
#     https://en.wikibooks.org/wiki/Ruby_Programming

def build_c(size)
c = Array.new(size)
for index in (0..size)
value = index * 9.0 / 5 + 32
c[index] = value
end
return c
end

def build_f(size)
f = Array.new(size)
for index in (0..size)
value = (index - 32) * 5.0 / 9
f[index] = value
end
return f
end

def display_array(name, array)
for index in (0..array.size - 1)
puts name + "[" + (index).to_s + "] = " + (array[index]).to_s
end
end

def find_temperature(c, f)
size = minimum(c.length, f.length)
begin
puts "Enter a temperature between 0 and " + ((size - 1)).to_s
temp = gets.chomp.to_i
end while (temp < 0 || temp > size - 1)
puts (temp).to_s + "° Celsius is " + (c[temp]).to_s + "° Fahrenheit"
puts (temp).to_s + "° Fahrenheit is " + (f[temp]).to_s + "° Celsius"
end

def minimum(value1, value2)
if value1 < value2
result = value1
else
result = value2
end

return result
end

def main()
c = build_c(100)
f = build_f(212)
display_array("C", c)
display_array("F", f)
find_temperature(c, f)
end

main()
```

## Try It

Copy and paste the code above into one of the following free online development environments or use your own Ruby compiler / interpreter / IDE.