I feel an answer with easily verifiable evidence would be best. These operations are so small that it is difficult to performance test them. == 1648 true === 1629 true control test 1575 true If you subtract off the control test, it looks like there is a ~30% difference in their speeds on my browser. … Read more
Two String objects will always be unequal to each other. Note that JavaScript has string primitive values as well as a String constructor to create wrapper objects. All object equality comparisons (especially with ===) are carried out as a test for reference equality. References to two different objects will of course never be equal to … Read more
In C++20 the way that the relational operators work was changed, notably with the introduction of the spaceship <=> operator. In particular, If you only provide operator==, then a != b is rewritten to !(a == b). From [over.match.oper]/3.4: The rewritten candidate set is determined as follows: For the relational ([expr.rel]) operators, the rewritten candidates … Read more
In C++20 the way that the relational operators work was changed, notably with the introduction of the spaceship <=> operator. In particular, If you only provide operator==, then a != b is rewritten to !(a == b). From [over.match.oper]/3.4: The rewritten candidate set is determined as follows: For the relational ([expr.rel]) operators, the rewritten candidates … Read more
For versions of numpy prior to 1.19, this is probably the best approach in situations that don’t specifically involve unit tests: >>> ((a == b) | (numpy.isnan(a) & numpy.isnan(b))).all() True However, modern versions provide the array_equal function with a new keyword argument, equal_nan, which fits the bill exactly. This was first pointed out by flyingdutchman; … Read more
Because the equality operator == coerces, or converts, the data type temporarily to see if it’s equal to the other operand, whereas === (the identity operator) doesn’t need to do any converting whatsoever and thus less work is done, which makes it faster.
You would not want the language to automatically rewrite a != b as !(a == b) when a == b returns something other than a bool. And there are a few reasons why you might make it do that. You may have expression builder objects, where a == b doesn’t and isn’t intended to perform … Read more
Take a look here: http://longgoldenears.blogspot.com/2007/09/triple-equals-in-javascript.html The 3 equal signs mean “equality without type coercion”. Using the triple equals, the values must be equal in type as well. 0 == false // true 0 === false // false, because they are of a different type 1 == “1” // true, automatic type conversion for value only … Read more