Ruby Number Examples: Integer, Float, zero and eqlUse numbers and the zero and eql methods. Convert strings into Integers and Floats.
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Numbers. Inside, the cave is still. Lights appear upon the cold dark surface wall. Each light is on or off (like a bit, which is set or not set). The lights could represent numbers.
Ruby examples. Numeric types and conversions are done in Ruby code (not usually in caves). Many programs use the Integer and Float built-in methods.
Here we convert string data to number types. A string may contain digits but not be a number. With the Integer conversion, we convert it to one. We also use Float.
Here We convert the string "1234" into an Integer. And we convert a string with floating-point data into a Float.
Then We add the 2 numbers together. This shows they are no longer strings, which could not be added in this way.
# Two strings with numeric contents.
Ruby program that converts strings, numbers
value1 = "1234"
value2 = "1234.5678"
# Convert strings to numbers.
number1 = Integer
number2 = Float
# Print numbers.
print "Number1: "
, number1, "\n"
print "Number2: "
, number2, "\n"
# Add numbers together.
# ... Could not be done with strings.
number3 = number1 + number2
# Print final number.
print "Number3: "
, number3, "\n"
We can directly use exponents, with the two-star operator. In this program, we raise a value to the power of two, and then to the power of three.
Tip More advanced mathematical operations are available as methods in the Math class.
# An initial value.
Ruby program that uses exponents
value = 3
# Square the value.
square = value ** 2
# Cube the value.
cube = value ** 3
# Display our results.
Zero() returns true or false. If the number is zero, it returns true. Otherwise, it returns false. Nonzero meanwhile returns the original number if it is not zero.
And If the number is zero, nonzero returns nil. So it returns the number with 0 changed to nil.
Ruby program that uses zero, nonzero
value = 0
puts "B" # Not reached.
value = 1
Unlike the "==" operator, eql compares types. So a floating point number, like 1.0, is not equal to an Integer number like 1. The == operator treats them as equal.
Tip Using the == operator is superior in most programs. The eql method just adds complexity—1.0 usually should equal 1.
Ruby program that uses eql
value1 = 1
value2 = 1.0
value3 = 1
puts "A" # Not reached.
if value1 == value2
With the rand method we generate a pseudo-random number. The srand method is used to seed our random number generator.
Some numeric operations can be done directly, with operators like + or minus. But many math methods exist, included for easy access. These handle more complex things like sqrt.
A summary. Tasks that involve numbers are often language-specific. In Ruby, we have many helpful operators available on numbers. We convert and manipulate numbers with ease.
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