Ruby

Ruby/Ruby-ArrayIndex_part1.rb

@@ -0,0 +1,21 @@
+def element_at(arr, index)
+    return arr[index]
+    # return the element of the Array variable `arr` at the position `index`
+    # arr.at(index) # or
+    # arr[index]
+end
+
+def inclusive_range(arr, start_pos, end_pos)
+    return arr[start_pos..end_pos]
+    # return the elements of the Array variable `arr` between the start_pos and end_pos (both inclusive)
+end
+
+def non_inclusive_range(arr, start_pos, end_pos)
+    return arr[start_pos...end_pos]
+    # return the elements of the Array variable `arr`, start_pos inclusive and end_pos exclusive
+end
+
+def start_and_length(arr, start_pos, length)
+    return arr[start_pos,length]
+    # return `length` elements of the Array variable `arr` starting from `start_pos`
+end

Ruby/Ruby-ArrayIndex_part2.rb

@@ -0,0 +1,27 @@
+def neg_pos(arr, index)
+    return arr[-index]
+    # return the element of the array at the position `index` from the end of the list
+    # Clue : arr[-index]
+end
+
+def first_element(arr)
+    return arr.first
+    # return the first element of the array
+    # arr.first
+end
+
+def last_element(arr)
+    return arr.last
+    # return the last element of the array
+    # arr.last
+end
+
+def first_n(arr, n)
+    return arr.take(n)
+    # return the first n elements of the array
+end
+
+def drop_n(arr, n)
+    return arr.drop(n)
+    # drop the first n elements of the array and return the rest
+end

Ruby/Ruby-Array_addition.rb

@@ -0,0 +1,19 @@
+def end_arr_add(arr, element)
+    # Add `element` to the end of the Array variable `arr` and return `arr`
+    arr.push(element)
+end
+
+def begin_arr_add(arr, element)
+    # Add `element` to the beginning of the Array variable `arr` and return `arr`
+    arr.unshift(element)
+end
+
+def index_arr_add(arr, index, element)
+    # Add `element` at position `index` to the Array variable `arr` and return `arr`
+    arr.insert(index,element)
+end
+
+def index_arr_multiple_add(arr, index)
+    # add any two elements to the arr at the index
+    arr.insert(index,1,2)
+end

Ruby/Ruby-Array_deletion.rb

@@ -0,0 +1,19 @@
+def end_arr_delete(arr)
+    # delete the element from the end of the array and return the deleted element
+    arr.pop
+end
+
+def start_arr_delete(arr)
+    # delete the element at the beginning of the array and return the deleted element
+    arr.shift
+end
+
+def delete_at_arr(arr, index)
+    # delete the element at the position #index
+    arr.delete_at(index)
+end
+
+def delete_all(arr, val)
+    # delete all the elements of the array where element = val
+    arr.delete(val)
+end

Ruby/Ruby-Array_initialization.rb

@@ -0,0 +1,5 @@
+# Initialize 3 variables here as explained in the problem statement
+
+array=Array.new
+array_1=[nil]
+array_2=[10,10]

Ruby/Ruby-Array_selection.rb

@@ -0,0 +1,19 @@
+def select_arr(arr)
+    # select and return all odd numbers from the Array variable `arr`
+      arr.select{|a| a%2==1}
+  end
+
+  def reject_arr(arr)
+    # reject all elements which are divisible by 3
+      arr.reject{|a| a%3==0}
+  end
+
+  def delete_arr(arr)
+    # delete all negative elements
+      arr.delete_if{|a| a<0}
+  end
+
+  def keep_arr(arr)
+    # keep all non negative elements ( >= 0)
+      arr.keep_if{|a| a>=0}
+  end

Ruby/Ruby-Control_structure_case.rb

@@ -0,0 +1,9 @@
+
+def identify_class(obj)
+    case obj
+    when Hacker, Submission, TestCase, Contest
+        puts "It's a #{obj.class}!"
+    else
+        puts "It's an unknown model"
+    end
+end

Ruby/Ruby-Control_structures_Infiniteloop.rb

@@ -0,0 +1,4 @@
+loop do
+    coder.practice
+    break if coder.oh_one?
+end

Ruby/Ruby-Control_structures_Untill.rb

@@ -0,0 +1,3 @@
+until coder.oh_one?
+    coder.practice
+end

Ruby/Ruby-Everything_is_object.rb

@@ -0,0 +1,2 @@
+# Enter your code here. Read input from STDIN. Print output to STDOUT
+print self

Ruby/Ruby-Introduction_HelloHackerrank.rb

@@ -0,0 +1,2 @@
+# Enter your code here. Read input from STDIN. Print output to STDOUT
+print "Hello HackerRank!!"

Ruby/Ruby-Object_methods.rb

@@ -0,0 +1,10 @@
+def odd_or_even(number)
+
+    number.even?
+
+ end
+
+ (0...gets.to_i).each do |i|
+     puts odd_or_even(gets.to_i)
+ end
+