[RUBY] 5th

Let's output hello \ _world

This time

Hello world

I would like to create a program that outputs.

Explanation of hello \ _world.rb

The method of issuing string with ruby ​​is as follows.

method effect
print Normal output(No line breaks)
puts Normal output(With line breaks)
printf Same as C printf
p debug output during coding
pp p print of p

The program outputs hello world in the order of puts, p, pp, printf, print.

Run hello \ _world.rb

The contents of the source code are as follows.

hello_world.rb



puts 'hello world '


p 'hello world by '


pp 'hello world by '


printf 'hello world  '

print 'hello world '

When you do this

 hello world
"hello world by "
"hello world by "
hello world  hello world

Was output.

Derived problem

Theme

> ruby hello_name.rb Ruby

If you are typed in

hello Ruby

Apply the ruby ​​code that outputs.

Commentary


puts ARGV[0]

ARGV is an argument vector, that is, an "array of arguments". It is used to pass arguments to the script when executing the script from the command line. The first argument is set in ARGV [0].

The following methods are available for outputting "hello Ruby" using this.

puts puts "hello"+ARGV[0]
puts puts "hello " #{ARGV[0]}
print print "hello #{ARGV[0]}\n"
print print "hello "+ARGV[0] +"\n"

From here, try executing the following code.

hello_name.rb



puts "hello #{ARGV[0]}"
puts "hello #{ARGV[0]}\n"
puts "hello " + ARGV[0] + "\n"

On the terminal

> ruby hello_name.rb Ruby

If you enter, the execution result will be

hello Ruby
hello Ruby
hello Ruby

It became.

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