Checking if two Dates have the same date info
You can use valueOf() or getTime(): a = new Date(1995,11,17); b = new Date(1995,11,17); a.getTime() === b.getTime() // prints true
equality
Why can a Python dict have multiple keys with the same hash?
Here is everything about Python dicts that I was able to put together (probably more than anyone would like to know; but the answer is comprehensive). A shout out to Duncan for pointing out that Python dicts use slots and leading me down this rabbit hole. Python dictionaries are implemented as hash tables. Hash tables … Read more
How default .equals and .hashCode will work for my classes?
Yes, the default implementation is Object’s (generally speaking; if you inherit from a class that redefined equals and/or hashCode, then you’ll use that implementation instead). From the documentation: equals The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this … Read more
Test for equality among all elements of a single numeric vector
Why not simply using the variance: var(x) == 0 If all the elements of x are equal, you will get a variance of 0. This works only for double and integers though. Edit based on the comments below: A more generic option would be to check for the length of unique elements in the vector … Read more
Correct way to override Equals() and GetHashCode() [duplicate]
You can override Equals() and GetHashCode() on your class like this: public override bool Equals(object obj) { var item = obj as RecommendationDTO; if (item == null) { return false; } return this.RecommendationId.Equals(item.RecommendationId); } public override int GetHashCode() { return this.RecommendationId.GetHashCode(); }
bash string equality [duplicate]
There’s no difference, == is a synonym for = (for the C/C++ people, I assume). See here, for example. You could double-check just to be really sure or just for your interest by looking at the bash source code, should be somewhere in the parsing code there, but I couldn’t find it straightaway.
How can I compare Lists for equality in Dart?
To complete Gunter’s answer: the recommended way to compare lists for equality (rather than identity) is by using the Equality classes from the following package import ‘package:collection/collection.dart’; Edit: prior to 1.13, it was import ‘package:collection/equality.dart’; E.g.: Function eq = const ListEquality().equals; print(eq([1,’two’,3], [1,’two’,3])); // => true The above prints true because the corresponding list elements … Read more
LINQ Select Distinct with Anonymous Types
Have a read through K. Scott Allen’s excellent post here: And Equality for All … Anonymous Types The short answer (and I quote): Turns out the C# compiler overrides Equals and GetHashCode for anonymous types. The implementation of the two overridden methods uses all the public properties on the type to compute an object’s hash … Read more
jQuery object equality
Since jQuery 1.6, you can use .is. Below is the answer from over a year ago… var a = $(‘#foo’); var b = a; if (a.is(b)) { // the same object! } If you want to see if two variables are actually the same object, eg: var a = $(‘#foo’); var b = a; …then … Read more
What’s the difference between == and .equals in Scala?
You normally use ==, it routes to equals, except that it treats nulls properly. Reference equality (rarely used) is eq.