Another update from ingydotnet^djgoku

Task/Call-a-function/Ruby/call-a-function-1.rb

@@ -0,0 +1,4 @@
+def foo() p "foo" end
+
+foo                             #=> "foo"
+foo()                           #=> "foo"

Task/Call-a-function/Ruby/call-a-function-10.rb

@@ -0,0 +1,13 @@
+#                                   return value        substance
+i = 3
+p 1 + i                         #=> 4                   1.+(i)
+p i < 5                         #=> true                i.<(5)
+p 2 ** i                        #=> 8                   2.**(i)
+p -i                            #=> -3                  i.-@()
+a = [1,2,3]
+p a[0]                          #=> 1                   a.[](0)
+a[2] = "0"                      #                       a.[]=(2,"0")
+p a << 5                        #=> [1, 2, "0", 5]      a.<<(5)
+p a & [4,2]                     #=> [2]                 a.&([4,2])
+p "abcde"[1..3]                 #=> "bcd"               "abcde".[](1..3)
+p "%2d %4s" % [1,"xyz"]         #=> " 1  xyz"           "%2d %4s".%([1,"xyz"])

Task/Call-a-function/Ruby/call-a-function-2.rb

@@ -0,0 +1,5 @@
+def foo arg; p arg end          # one argument
+
+foo(1)                          #=> 1
+foo "1"                         #=> "1"
+foo [0,1,2]                     #=> [0, 1, 2]   (one Array)

Task/Call-a-function/Ruby/call-a-function-3.rb

@@ -0,0 +1,6 @@
+def foo(x=0, y=x, flag=true) p [x,y,flag] end
+
+foo                             #=> [0, 0, true]
+foo(1)                          #=> [1, 1, true]
+foo(1,2)                        #=> [1, 2, true]
+foo 1,2,false                   #=> [1, 2, false]

Task/Call-a-function/Ruby/call-a-function-4.rb

@@ -0,0 +1,4 @@
+def foo(*args) p args end
+
+foo                             #=> []
+foo(1,2,3,4,5)                  #=> [1, 2, 3, 4, 5]

Task/Call-a-function/Ruby/call-a-function-5.rb

@@ -0,0 +1,3 @@
+def foo(id:0, name:"", age:0) p [id, name, age] end
+
+foo(age:22, name:"Tom")         #=> [0, "Tom", 22]

Task/Call-a-function/Ruby/call-a-function-6.rb

@@ -0,0 +1,12 @@
+def foo(a,b) a + b end
+
+bar = foo 10,20
+p bar                           #=> 30
+p foo("abc","def")              #=> "abcdef"
+
+# return multiple values
+def sum_and_product(a,b) return a+b,a*b end
+
+x,y = sum_and_product(3,5)
+p x                             #=> 8
+p y                             #=> 15

Task/Call-a-function/Ruby/call-a-function-7.rb

@@ -0,0 +1,12 @@
+puts "OK!"                      # Kernel#puts
+raise "Error input"             # Kernel#raise
+Integer("123")                  # Kernel#Integer
+rand(6)                         # Kernel#rand
+throw(:exit)                    # Kernel#throw
+
+# method which can be seen like a reserved word.
+attr_accessor                   # Module#attr_accessor
+include                         # Module#include
+private                         # Module#private
+require                         # Kernel#require
+loop { }                        # Kernel#loop

Task/Call-a-function/Ruby/call-a-function-8.rb

@@ -0,0 +1,14 @@
+class Array
+  def sum(init=0, &blk)
+    if blk
+      inject(init){|s, n| s + blk.call(n)}
+    else
+      inject(init){|s, n| s + n}
+    end
+  end
+end
+
+ary = [1,2,3,4,5]
+p ary.sum                               #=> 15
+p ary.sum(''){|n| (-n).to_s}            #=> "-1-2-3-4-5"
+p (ary.sum do |n| n * n end)            #=> 55

Task/Call-a-function/Ruby/call-a-function-9.rb

@@ -0,0 +1,6 @@
+def foo(a,b,c) p [a,b,c] end
+
+args = [1,2,3]
+foo *args                       #=> [1, 2, 3]
+args = [1,2]
+foo(0,*args)                    #=> [0, 1, 2]