Here on “Ask a Question,” Flatiron School’s chat/screen share support tool for students struggling with their code, we frequently see certain types of errors. Here are some common Ruby problems and how to solve them.
Syntax Errors
Nothing will work, and you won’t even be able to use debugging tools effectively, if you have a syntax error or several syntax errors. Does every do have an end? Review your if/else statements; do you have an else without an if, or an if without an end? Do you have extra ends in other methods, or at the bottom of the file you are working in? Indent your code properly for easy debugging; in the example below, each end is lined up with its corresponding if or do:
def num_points_scored(name)
game_hash.each do |location, team_data|
team_data[:players].each do |player_name, player_data|
if name == player_name
return player_data[:points]
end
end
end
end
Loops
Is your code stuck in an infinite loop? Or conversely, did you accidentally put a return inside your loop instead of after you have finished iterating over every item in an array? A return inside a loop will stop the loop. Notice how far down the return is in the following method. You could insert a binding.pry here and move it around to see what you are getting in different locations in your code before finally settling on a location for the return.
def team_names
names_array = []
game_hash.each do |location, team_data|
team_data.each do |key, value|
if key == :team_name
names_array << value
end
end
end
return names_array
end
Equals vs. Comparison
Using the code example above, if you are defining a variable, you use one equals sign, such as names_array = []. If you are trying to compare something, you use a double equals sign, such as if key == :team_name. Often students will try to use a single equals sign when making a comparison. If you are trying to compare two things, you need two equals signs.
Data Types
Pay attention to the type of data you are working with. Array methods such as collect and push can’t be used on a string or a hash. If you are not sure what type of data you are working with, check the data that’s being passed into your method, or use a binding.pry to inspect it.
Conclusion
Even experienced coders make these errors. If everything should work, but it doesn’t, check for these common culprits, and you may have your answer.