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How unique is UUID?
...om numbers. However, it seems to me that given enough time, it would eventually repeat it self, just by pure chance. Is there a better system or a pattern of some type to alleviate this issue?
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How to search in array of object in mongodb
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Use $elemMatch to find the array of particular object
db.users.findOne({"_id": id},{awards: {$elemMatch: {award:'Turing Award', year:1977}}})
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How do I concatenate two strings in C?
...-terminator.
char* concat(const char *s1, const char *s2)
{
const size_t len1 = strlen(s1);
const size_t len2 = strlen(s2);
char *result = malloc(len1 + len2 + 1); // +1 for the null-terminator
// in real code you would check for errors in malloc here
memcpy(result, s1, len1);
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Detect if an input has text in it using CSS — on a page I am visiting and do not control?
... script will work in Chrome, or Firefox with Greasemonkey or Scriptish installed, or in any browser that supports userscripts (i.e. most browsers, except IE).
See a demo of the limits of CSS plus the javascript solution at this jsBin page.
// ==UserScript==
// @name _Dynamically style inputs b...
Why use static_cast(x) instead of (int)x?
...e main reason is that classic C casts make no distinction between what we call static_cast<>(), reinterpret_cast<>(), const_cast<>(), and dynamic_cast<>(). These four things are completely different.
A static_cast<>() is usually safe. There is a valid conversion in the...
How to programmatically take a screenshot on Android?
... save the file:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
And this is the code (running in an Activity):
private void takeScreenshot() {
Date now = new Date();
android.text.format.DateFormat.format("yyyy-MM-dd_hh:mm:ss", now);
try {
//...
How to use a variable to specify column name in ggplot
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"cumbersome"? Non-standard evaluation in R is ironically the most cumbersome "feature" I have ever encountered in a programming language. Truly maddening.
– jessexknight
Feb 4 at 18:10
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Aliases in Windows command prompt
...ommand dropbox research points to the same directory as research.
As Rivenfall pointed out, it is a good idea to include a command that allows for convenient editing of the alias.cmd file. See alias above. If you are in a cmd session, enter cmd to restart cmd and reload the alias.cmd file.
When ...
Adding rounded corner and drop shadow to UICollectionViewCell
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Neither of these solutions worked for me. If you place all your subviews into the UICollectionViewCell content view, which you probably are, you can set the shadow on the cell's layer and the border on the contentView's layer to achieve both results.
cell.contentView.layer.corne...
UIView Infinite 360 degree rotation animation?
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This might help some one, [view.layer removeAllAnimations]; to stop animation when needed.
– arunit21
Aug 22 '14 at 13:57
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