” == ‘0’ // false The left hand side is an empty string, and the right hand side is a string with one character. They are false because it is making a comparison between two un identical strings (thanks Niall). 0 == ” // true Hence, why this one is true, because 0 is falsy … Read more
It allows you to do your own memory management. Usually this will get you at best marginally improved performance, but sometimes it’s a big win. For example, if your program is using a large number of standard-sized objects, you might well want to make a pool with one large memory allocation. This sort of thing … Read more
The equality operator will attempt to make the data types the same before making the comparison. On the other hand, the identity operator requires both data types to be the same as a prerequisite. There are quite a few other posts out there similar to this questions. See: How do the PHP equality (== double … Read more
I’ll answer this question incrementally. Let’s start with the = equivalence predicate. The = predicate is used to check whether two numbers are equal. If you supply it anything else but a number then it will raise an error: (= 2 3) => #f (= 2.5 2.5) => #t (= ‘() ‘()) => error The … Read more
Consider this simple problem: class Number: def __init__(self, number): self.number = number n1 = Number(1) n2 = Number(1) n1 == n2 # False — oops So, Python by default uses the object identifiers for comparison operations: id(n1) # 140400634555856 id(n2) # 140400634555920 Overriding the __eq__ function seems to solve the problem: def __eq__(self, other): “””Overrides … Read more
There are a couple of ways. My preferred way is to attach a function to the ajaxStart/Stop events on the element itself. $(‘#loadingDiv’) .hide() // Hide it initially .ajaxStart(function() { $(this).show(); }) .ajaxStop(function() { $(this).hide(); }) ; The ajaxStart/Stop functions will fire whenever you do any Ajax calls. Update: As of jQuery 1.8, the documentation … Read more