Returns zero.
Returns self.
Returns the absolute value of num.
12.abs #=> 12 (-34.56).abs #=> 34.56 -34.56.abs #=> 34.56
Numeric#magnitude is an alias for Numeric#abs.
Returns num truncated (toward zero) to a precision of ndigits decimal digits (default: 0).
Numeric implements this by converting its value to a Float and invoking Float#truncate.
Returns true if num is less than 0.
Returns the numerator.
Returns the denominator (always positive).
Returns an array of characters in str. This is a shorthand for str.each_char.to_a.
If a block is given, which is a deprecated form, works the same as each_char.
Concatenates the given object(s) to str. If an object is an Integer, it is considered a codepoint and converted to a character before concatenation.
concat can take multiple arguments, and all the arguments are concatenated in order.
a = "hello " a.concat("world", 33) #=> "hello world!" a #=> "hello world!" b = "sn" b.concat("_", b, "_", b) #=> "sn_sn_sn"
See also String#<<, which takes a single argument.
Returns a new String with the last character removed. If the string ends with \r\n, both characters are removed. Applying chop to an empty string returns an empty string. String#chomp is often a safer alternative, as it leaves the string unchanged if it doesn’t end in a record separator.
"string\r\n".chop #=> "string" "string\n\r".chop #=> "string\n" "string\n".chop #=> "string" "string".chop #=> "strin" "x".chop.chop #=> ""
Returns a new String with the given record separator removed from the end of str (if present). If $/ has not been changed from the default Ruby record separator, then chomp also removes carriage return characters (that is it will remove \n, \r, and \r\n). If $/ is an empty string, it will remove all trailing newlines from the string.
"hello".chomp #=> "hello" "hello\n".chomp #=> "hello" "hello\r\n".chomp #=> "hello" "hello\n\r".chomp #=> "hello\n" "hello\r".chomp #=> "hello" "hello \n there".chomp #=> "hello \n there" "hello".chomp("llo") #=> "he" "hello\r\n\r\n".chomp('') #=> "hello" "hello\r\n\r\r\n".chomp('') #=> "hello\r\n\r"
Processes str as for String#chop, returning str, or nil if str is the empty string. See also String#chomp!.
Modifies str in place as described for String#chomp, returning str, or nil if no modifications were made.
Returns the absolute value of float.
(-34.56).abs #=> 34.56 -34.56.abs #=> 34.56 34.56.abs #=> 34.56
Float#magnitude is an alias for Float#abs.
Returns float truncated (toward zero) to a precision of ndigits decimal digits (default: 0).
When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.
Returns a floating point number when ndigits is positive, otherwise returns an integer.
2.8.truncate #=> 2 (-2.8).truncate #=> -2 1.234567.truncate(2) #=> 1.23 34567.89.truncate(-2) #=> 34500
Note that the limited precision of floating point arithmetic might lead to surprising results:
(0.3 / 0.1).truncate #=> 2 (!)
Returns true if float is less than 0.
Returns the numerator. The result is machine dependent.
n = 0.3.numerator #=> 5404319552844595 d = 0.3.denominator #=> 18014398509481984 n.fdiv(d) #=> 0.3
See also Float#denominator.
Returns the denominator (always positive). The result is machine dependent.
See also Float#numerator.
Returns a simpler approximation of the value (flt-|eps| <= result <= flt+|eps|). If the optional argument eps is not given, it will be chosen automatically.
0.3.rationalize #=> (3/10) 1.333.rationalize #=> (1333/1000) 1.333.rationalize(0.01) #=> (4/3)
See also Float#to_r.
Calls the block once for each entry in the named directory, passing the filename of each entry as a parameter to the block.
If no block is given, an enumerator is returned instead.
Dir.foreach("testdir") {|x| puts "Got #{x}" }
produces:
Got . Got .. Got config.h Got main.rb
Returns an array containing all of the filenames except for “.” and “..” in the given directory. Will raise a SystemCallError if the named directory doesn’t exist.
The optional encoding keyword argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.
Dir.children("testdir") #=> ["config.h", "main.rb"]
Calls the block once for each entry in this directory, passing the filename of each entry as a parameter to the block.
If no block is given, an enumerator is returned instead.
d = Dir.new("testdir") d.each {|x| puts "Got #{x}" }
produces:
Got . Got .. Got config.h Got main.rb