Lesson 1 of 23 · Ruby 3.4
Run Ruby and inspect values
Run a short Ruby program and choose how to display its values.
Learn
A Ruby program evaluates code in order. A value can be a number such as 12 or text inside quotes such as "Welcome". An expression produces a value: 12 + 3 adds two numbers. Press Run to execute the code in the editor.
puts displays a value as text on its own line. p displays an inspection form that is useful when exploring values; for a string, it includes surrounding quotes. Both are methods supplied by Ruby. These examples call them by writing the method name followed by the value to display.
Write each instruction on a new line. Blank lines can separate related instructions. A # outside a quoted string starts a comment that Ruby ignores through the end of that line.
Example
puts "Welcome"
puts 12 + 3
p "Welcome"Experiment
Run this short sign message. Replace only the second puts with p, then compare how the same text is displayed.
Predict which lines display something, then run. Add puts before the calculation so that you can inspect its value too.