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Learning ruby - day 1
Hey guys, welcome to my blog recording my ruby self-taught process
I decided to learn this amazing language while I was trying to solving some ruby challenges to get my tenth badge in HackerRank
Ok let's do it
print "Hello World!!!"
Output
PS D:\Workplace> ruby hello-world.rb
Hello World!!!
print "\n" equals puts
print "First line "
print "still first line\n"
puts "Second line"
puts "Thirld line"
Output
First line still first line
Second line
Thirld line
print else
Output
main
check whether the num is even or odd
num = 2
print num.even?
Output
true
print the quotient of num and 2
num = 2
num.div 2
print num
Output
1
print the value of each member in array to the power of 2
array = [1, 2, 3, 4, 5]
array.each do |num|
puts num.pow 2
end
Output
1
4
9
16
25
print ASCII chars of any decimal number in array if number is not odd
def print_char(array)
array.each do |num|
puts num.chr unless num.odd?
end
end
array = [65, 66, 67, 68, 69, 70, 71]
print_char(array)
Output
B
D
F
Working on single element
Delete last element
arr.pop
Delete first element
arr.shift
Delete element at position a given position
arr.delete_at(2)
Working on multiple elements
Delete all occurrences of a given element
arr.delete(5)
Delete elements if
arr.delete_if {|a| a < 2}
Delete elements unless
arr.keep_if {|a| a < 4}
Create subarray
Select elements from array to subarray
arr2 = arr.select {|a| a > 2}
print arr2
Reject elements from array to subarray
arr2 = arr.reject {|a| a > 2}
Reject elements from array till returns false for the first time
arr2 = arr.drop_while {|a| a > 1}
# initialize and set default value
empty_hash = Hash.new
empty_hash.default = 1
# or
default_hash = Hash.new(1)
Set value
new_hash = {"key1" => 12, "key2" => 50}
# or
new_hash = Hash.new
new_hash["key1"] = 12
new_hash["key2"] = 50
# or
new_hash.store("key1", 12)
new_hash.store(1512032, 50)
Loop with hash
hash.each do |key, value|
puts key
puts value
end
# or
hash.each do |array|
# now key is array[0], value is array[1]
puts array[0]
puts array[1]
end
Delete pair
# Delete specific key
hash.delete("key1")
# Delete if
hash.keep_if {|key, value| key.is_a? Integer}
# or
hash.delete_if {|key, value|key.even? }
i = 0
loop do
puts i
i += 1
break if i == 10
end
Output
1
2
3
4
5
6
7
8
9
10
We have learned how to print output
How to do some basic loop and function
Learned some common methods of array and a dictionary-like data structures called hash
I'd like to thank HackerRank for giving me a chance to acknowledge and be interesting in this cool language
If guys found Ruby is fascinating, please come to the link below and solve some Ruby challenges with me
If you have any question or suggestion, please let me know at the comment section below.
OK I'm going to wrap this up here
Thanks for reading my blog
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