In programming, the faster you get feedback from your code, the more productive you can be.
For example, suppose you're going to use the Javascript Date class in a web page to do some time calculations. Do you:
- Write some code, save the file, reload the page, look at the results, and repeat?
- Open a Javascript console (like Chome Developer Tools or Firebug) and experiment?
The second method gives you instant feedback. This means you can find the right approach more quickly and not lose focus in the meantime. The same is true when coding Ruby: if you want to see what Array#select does, irb will give you much faster feedback than a Rails app.
Other ways you can get feedback faster include:
- To learn more about Git, create a temporary folder and a dummy project: mkdir ~/test; cd ~/test; git init; echo 'hello' > test.txt; git add .; git commit -m"first"; Now you can experiment: branch and merge, rebase, and whatever else you want to try without fear of screwing up a real project. When you're satisfied, just delete that folder.
- If you're thinking of adding a command to one of your runtime configuration files, like .bashrc or .vimrc, run the command directly first and see what it does.
- Take the time to make your automated tests run faster: you'll be more likely to run them often and less likely to lose focus when you do.