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Regular expression for floating point numbers
...al numbers, such as hex and octal, see my answer to How do I identify if a string is a number?.
If you want to validate that an input is a number (rather than finding a number within the input), then you should surround the pattern with ^ and $, like so:
^[+-]?([0-9]+([.][0-9]*)?|[.][0-9]+)$
Irr...
How to delete migration files in Rails 3
...
I usually:
Perform a rake db:migrate VERSION=XXX on all environments, to the version before the one I want to delete.
Delete the migration file manually.
If there are pending migrations (i.e., the migration I removed was not the...
What is the difference between SessionState and ViewState?
... saved on the server, ViewState is saved in the page.
Session state is usually cleared after a period of inactivity from the user (no request happened containing the session id in the request cookies).
The view state is posted on subsequent post back in a hidden field.
...
How often does python flush to a file?
...t size.
A negative buffering means to use the system default, which is usually line buffered for tty devices and fully buffered for other files.
If omitted, the system default is used.
code:
bufsize = 0
f = open('file.txt', 'w', buffering=bufsize)
...
What is the difference between tree depth and height?
... node" it is not correct , the leaf must be the one which is deepest among all the leaves of the given node.
– mightyWOZ
Jul 14 '16 at 7:53
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|...
What does this symbol mean in JavaScript?
...avaScript?
Why does JavaScript handle the plus and minus operators between strings and numbers differently?
|, &, ^, ~ — Single pipe, ampersand, circumflex, tilde: bitwise OR, AND, XOR, & NOT operators
What do these JavaScript bitwise operators do?
How to: The ~ operator?
Is there a ...
Delete first character of a string in Javascript
I want to delete the first character of a string, if the first character is a 0. The 0 can be there more than once.
14 Ans...
How to use JUnit to test asynchronous processes
... of time. Your test would look something like this:
CompletableFuture<String> future = new CompletableFuture<>();
executorService.submit(new Runnable() {
@Override
public void run() {
future.complete("Hello World!");
}
});
assertEquals("Hell...
How to capitalize the first letter of a String in Java?
I am using Java to get a String input from the user. I am trying to make the first letter of this input capitalized.
55 ...
What is a raw type and why shouldn't we use it?
...ass Inner { }
static class Nested { }
public static void main(String[] args) {
MyType mt; // warning: MyType is a raw type
MyType.Inner inn; // warning: MyType.Inner is a raw type
MyType.Nested nest; // no warning: not parameterized type
MyTyp...