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Test if string is a number in Ruby on Rails
...def is_number? string
true if Float(string) rescue false
end
And then call it like this:
my_string = '12.34'
is_number?( my_string )
# => true
Extend String Class.
If you want to be able to call is_number? directly on the string instead of passing it as a param to your helper function, t...
Why not use Double or Float to represent currency?
...power of 10 to get 1/3. You could settle on a long sequence of 3's and a small exponent, like 333333333 * 10-10, but it is not accurate: if you multiply that by 3, you won't get 1.
However, for the purpose of counting money, at least for countries whose money is valued within an order of magnitude...
Making macOS Installer Packages which are Developer ID ready
Note: This is for OS X Installer packages only, packages for submission to the Mac App Store follow different rules.
5 ...
How well is Unicode supported in C++11?
...ization library
Input/output library
Regular expressions library
I think all but the first one provide terrible support. I'll get back to it in more detail after a quick detour through your other questions.
Does std::string do what it should?
Yes. According to the C++ standard, this is what ...
Is it possible to GROUP BY multiple columns using MySQL?
...garding SUM using with GROUP BY. If GROUP BY only by one column, then SUMs all values of each distinct (different) the column value sqlfiddle.com/#!9/1cbde2/2. If GROUP BY two columns. Then mysql at first checks if for the first column value there are different values in the second column. If yes, t...
How do I completely uninstall Node.js, and reinstall from beginning (Mac OS X)
My version of node is always v0.6.1-pre even after I install brew node and NVM install v0.6.19.
28 Answers
...
Calling filter returns [duplicate]
...ten) want to do the filtering in a lazy sense -- You don't need to consume all of the memory to create a list up front, as long as the iterator returns the same thing a list would during iteration.
If you're familiar with list comprehensions and generator expressions, the above filter is now (alm...
Difference between JSON.stringify and JSON.parse
...pt object into JSON text and stores that JSON text in a string, eg:
var my_object = { key_1: "some text", key_2: true, key_3: 5 };
var object_as_string = JSON.stringify(my_object);
// "{"key_1":"some text","key_2":true,"key_3":5}"
typeof(object_as_string);
// "string"
JSON.parse turns a...
How much of a git sha is *generally* considered necessary to uniquely identify a change in a given c
...of it colliding would be negligible, how much of the SHA substring is generally required?
5 Answers
...
glob exclude pattern
...
Really interesting solution! But my case is going to be extremely slow to make a read twice. Also if the content of a folder is big on an network directory, is going to be slow again. But in any case, really handy.
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