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When to use StringBuilder in Java [duplicate]
It is supposed to be generally preferable to use a StringBuilder for string concatenation in Java. Is this always the case?
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How do I copy an object in Java?
...as also a clone method which can be used to copy the object, but don't use it. It's way too easy to create a class and do improper clone method. If you are going to do that, read at least what Joshua Bloch has to say about it in Effective Java.
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Regex empty string or email
...l accept an empty string. Is this possible through Regex only? Accepting either empty string or email only? I want to have this on Regex only.
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What is the difference between `new Object()` and object literal notation?
..., other than that your second one creates an object and adds a property to it. But literal notation takes less space in the source code. It's clearly recognizable as to what is happening, so using new Object(), you are really just typing more and (in theory, if not optimized out by the JavaScript e...
Auto margins don't center image in page
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add display:block; and it'll work. Images are inline by default
To clarify, the default width for a block element is auto, which of course fills the entire available width of the containing element.
By setting the margin to auto, the browser assi...
How to get an array of unique values from an array containing duplicates in JavaScript? [duplicate]
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Edited
ES6 solution:
[...new Set(a)];
Alternative:
Array.from(new Set(a));
Old response. O(n^2) (do not use it with large arrays!)
var arrayUnique = function(a) {
return a.reduce(function(p, c) {
if (p.index...
When is it practical to use Depth-First Search (DFS) vs Breadth-First Search (BFS)? [closed]
...stand the differences between DFS and BFS, but I'm interested to know when it's more practical to use one over the other?
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PHP - how to best determine if the current invocation is from CLI or web server?
...is from the command line (CLI) or from the web server (in my case, Apache with mod_php).
18 Answers
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How do I test an AngularJS service with Jasmine?
...order to the service to be instantiated angular.injector has to be called with the module where our service is defined. Then, we can ask to the new injector object for the service and its only then when the service is finally instantiated.
Something like this works:
describe('myService test', func...
C# 4 default parameter values: How to assign a default DateTime/object value? [duplicate]
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DateTime cannot be used as a constant but you could make it a nullable type (DateTime?) instead.
Give the DateTime? a default value of null, and if it is set to null at the start of your function, then you can initialize it to any value you want.
static void test(DateTime? dt = n...