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Return all enumerables with yield return at once; without looping through
...mportant difference between the two implementations though: this one will call all of the methods immediately, even though it will only use the returned iterators one at a time. Your existing code will wait until it's looped through everything in GetMoreErrors() before it even asks about the next er...
How to write :hover condition for a:before and a:after?
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This depends on what you're actually trying to do.
If you simply wish to apply styles to a :before pseudo-element when the a element matches a pseudo-class, you need to write a:hover:before or a:visited:before instead. Notice the pseudo-element comes after ...
What's the difference between the data structure Tree and Graph?
Academically speaking, what's the essential difference between the data structure Tree and Graph? And how about the tree based search and Graph based search?
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Parallel.ForEach vs Task.Factory.StartNew
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The first is a much better option.
Parallel.ForEach, internally, uses a Partitioner<T> to distribute your collection into work items. It will not do one task per item, but rather batch this to lower the overhead involved.
The second option will schedule a...
Visual Studio : short cut Key : Duplicate Line
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In Visual Studio 2017 (pre v15.6)
(edit) This feature is now built-in in VS2017: Ctrl + E, V duplicates a line if nothing is selected, or duplicates selection. You can assign it to a different key combination, or find it in the menu:
See this reference for more information.
Pre VS2017, built-i...
String, StringBuffer, and StringBuilder
...o, using String for logic operations is rather slow, and is not advised at all, since the JVM converts the String to a StringBuffer in the bytecode. A lot of overhead is wasted converting from String to StringBuffer and then back to String again.
– Pieter van Niekerk
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Unit tests vs Functional tests
...- testing an individual unit, such as a method (function) in a class, with all dependencies mocked up.
Functional Test - AKA Integration Test, testing a slice of functionality in a system. This will test many methods and may interact with dependencies like Databases or Web Services.
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var functionName = function() {} vs function functionName() {}
...);
function functionTwo() {
console.log("Hello!");
}
Historically, function declarations defined within blocks were handled inconsistently between browsers. Strict mode (introduced in ES5) resolved this by scoping function declarations to their enclosing block.
'use strict';
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What is the difference between a deep copy and a shallow copy?
What is the difference between a deep copy and a shallow copy?
31 Answers
31
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Best way to serialize an NSData into a hexadeximal string
.... I profiled this with a 2MB file on my iPhone 5. Time comparison was 0.05 vs 12 seconds. Memory footprint is negligible with this method while the other method grew the heap to 70MBs!
- (NSString *) hexString
{
NSUInteger bytesCount = self.length;
if (bytesCount) {
const char *hexC...