Write to file

examples/ruby/write_to_file.rb

f = File.new('out.txt', 'w')
f.write("Hello World!\n")
f.write("Hello Foo!\n")
f.close     

If we run this it will create the file out.txt if it did not exists before or it will overwrite it if it existed earlier. Any previous content will be removed.

Append to file

If the second parameter to the new method is 'a' and not 'w' then we are goint to append to the end of the file. This mean is the file already has some content, it will be kept and anything new will be added to the end. If the file did not exist earlier then this too will create it.

examples/ruby/append_to_file.rb

f = File.new('out.txt', 'a')
f.write("Hello World!\n")
f.write("Hello Foo!\n")
f.close