ruby使用技巧
翻出来一篇很老的东西，有些已经不用了，总之，抄回来，看看吧
1 - Extract regular expression matches quickly
A typical way to extract data from text using a regular expression is to use the match method. There is a shortcut, however, that can take the pain out of the process:
3 - Format decimal amounts quickly
Formatting floating point numbers into a form used for prices can be done with sprintf or, alternatively, with a formatting interpolation:
4 - Interpolate text quickly
The formatting interpolation technique from #3 comes out again, this time to insert a string inside another:
You can use an array of elements to substitute in too:
5 - Delete trees of files
Don't resort to using the shell to delete directories. Ruby comes with a handy file utilities library called FileUtils that can do the hard work:
# Output:
# Added to queue
# Added to queue
# ["hello", "world"]
2009 Update: Be careful here - this one can sting you in the butt if your first expression returns nil even when it works. A key example of this is with the puts method which returns nil even after printing the supplied arguments.
10 - Do something only if the code is being implicitly run, not required
This is a very common pattern amongst experienced Ruby developers. If you're writing a Ruby script that could be used either as a library OR directly from the command line, you can use this trick to determine whether you're running the script directly or not:
12 - Use ranges instead of complex comparisons for numbers
No more if x > 1000 && x < 2000 nonsense. Instead:
puts x == 10 ? "x is ten" : "x is not ten"
# Or.. an assignment based on the results of a ternary operation:
LOG.sev_threshold = ENVIRONMENT == :development ? Logger::DEBUG : Logger::INFO
15 - Nested Ternary Operators
It can be asking for trouble but ternary operators can be nested within each other (after all, they only return objects, like everything else):
I commonly see methods using this sort of pattern:
