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count vs length vs size in a collection
...), there may be 10 characters in a string, but storage is reserved for 20. It also may refer to number of elements - check source/documentation.
Capacity() - used to specifically refer to allocated space in collection and not number of valid elements in it. If type has both "capacity" and "size" de...
Test if characters are in a string
...follow
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edited Apr 14 at 17:04
TMS
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How do I create a readable diff of two spreadsheets using git diff?
We have a lot of spreadsheets (xls) in our source code repository. These are usually edited with gnumeric or openoffice.org, and are mostly used to populate databases for unit testing with dbUnit . There are no easy ways of doing diffs on xls files that I know of, and this makes merging extremely...
Linux: copy and create destination dir if it does not exist
...nd (or probably an option to cp) that creates the destination directory if it does not exist.
21 Answers
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Is it secure to store passwords as environment variables (rather than as plain text) in config files
I work on a few apps in rails, django (and a little bit of php), and one of the things that I started doing in some of them is storing database and other passwords as environment variables rather than plain text in certain config files (or in settings.py, for django apps).
...
How to check for valid email address? [duplicate]
Is there a good way to check a form input using regex to make sure it is a proper style email address? Been searching since last night and everybody that has answered peoples questions regarding this topic also seems to have problems with it if it is a subdomained email address.
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ALTER TABLE without locking the table?
...ySQL, the whole table is read-locked (allowing concurrent reads, but prohibiting concurrent writes) for the duration of the statement. If it's a big table, INSERT or UPDATE statements could be blocked for a looooong time. Is there a way to do a "hot alter", like adding a column in such a way that th...
Does return stop a loop?
...
Yes, return stops execution and exits the function. return always** exits its function immediately, with no further execution if it's inside a for loop.
It is easily verified for yourself:
function returnMe() {
for (var i = 0; i < 2; i++) {
if (i...
When and how should I use a ThreadLocal variable?
... object (I'm looking at you, SimpleDateFormat). Instead, give each thread its own instance of the object.
For example:
public class Foo
{
// SimpleDateFormat is not thread-safe, so give one to each thread
private static final ThreadLocal<SimpleDateFormat> formatter = new ThreadLocal...
Avoid synchronized(this) in Java?
... an
"accidentally" variant)
I'm more worried about accidentally. What it amounts to is that this use of this is part of your class' exposed interface, and should be documented. Sometimes the ability of other code to use your lock is desired. This is true of things like Collections.synchronize...