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Find the distance between two points
ruby
distance = Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1))
Zero pad a number
Given the number 42, pad it to 8 characters like 00000042
ruby
42.to_s.rjust(8,"0")
"%08d" % 42
Right Space pad a number
Given the number 1024 right pad it to 6 characters
"1024 "
ruby
num = 1024
s = 1024.to_s
puts s + (6-s.length) * " "
s = 1024.to_s
puts s + (6-s.length) * " "
Format a decimal number
Format the number 7/8 as a decimal with 2 places: 0.88
ruby
(7.0/8.0*100).round/100.0
Left Space pad a number
Given the number 73 left pad it to 10 characters
" 73"
ruby
73.to_s.rjust(10)
Generate a random integer in a given range
Produce a random integer between 100 and 200 inclusive
ruby
randomInt = rand(200-100+1)+100;
Generate a repeatable random number sequence
Initialise a random number generator with a seed and generate five decimal values. Reset the seed and produce the same values.
ruby
srand(12345)
first = (1..5).collect {rand}
srand(12345)
second = (1..5).collect {rand}
puts first == second
first = (1..5).collect {rand}
srand(12345)
second = (1..5).collect {rand}
puts first == second
