Architectural_Design_with_SketchUp

Architectural Design with SketchUp
Beyond IF, other control structures are UNLESS, which works similar to IF and uses the
same structure, and CASE, which applies code based on variable switches.
Repeating Things: FOR, WHILE, and More
Whenever you need to repeat code in a loop, Ruby actually has various ways to let you do
this. Let’s look at some of them. First is the “classic” for loop:
for i in 1..10
print i
end
As you can see, this uses a range (1..10) to describe how often this code should repeat.
Another version is the WHILE statement:
num = 1
while num < 10 do
print num
num += 1
end
You can also use the elegant each method, as in:
(0..10).each { |i|
print i
}
In this form, i is assigned to each element. Although in our case this simply becomes a
numeric index, we will use this extensively in SketchUp coding later to iterate through objects.
Finally, the integer object also has a times method that you can employ like this. Any
(multiline) code in the curly brackets will be executed 10 times in this case.
10.times { |i|
print i
}
Making It Work: Some More Ruby Syntax Details
You’ve already seen that Ruby does not require you to tell it when a line ends (many other
programming languages need a semicolon there). There are more language-specific things
you need to know:
NN
A one-line comment starts with a #. Anything after the #, until the end of the line, is
ignored by Ruby.
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