# Variables

Hi all. I am very very new on that so don’t be mad with my ignorance. I am just trying to create a simple algorithm that can find the Greatest Common Divisor of two numbers and gest what … I can find the way to insert those two numbers. The io. read just don’t work. Any suggestions on that ?

Check the keyboard functions from the doc?

@Thomas

If you get stuck and need an example to look at, here is a simple program.

``````
function setup()
displayMode(FULLSCREEN)
showKeyboard()
fontSize(40)
fill(255)
str=""
nbr=1
g1=0;g2=0;g3=0
n1=0;n2=0
a1=0;a2=0
end

function draw()
background(30,30,0,255)

if nbr==1 then
str2="1st"
elseif nbr==2 then
str2="2nd"
a1=n1;a2=0
n3=0
end

text(string.format("Enter %s number then press return",str2),WIDTH/2,650)

if n1>0 then
a1=n1;a2=0
g3=0
end
if n2>0 then
a2=n2
end

str3=string.format("GCD (%d,%d) = %d",a1,a2,g3)
text(str3,WIDTH/2,500)

if nbr==3 then
gcd()
n1=0;n2=0
nbr=1
end
end

function keyboard(key)
if key == RETURN then    -- return key pressed
str=""
nbr = nbr + 1
else
if key>="0" and key<="9" then
str=str..key
if nbr==1 then
n1=tonumber(str)
elseif nbr==2 then
n2=tonumber(str)
end
end
end
end

function gcd()
g1=n1;g2=n2;g3=n1
while g1~=g2 do
g3=math.abs(g1-g2)
g4=math.min(g1,g2)
g1=g3;g2=g4
end
end

``````

…and it works … thanx again