I’m going to heavily quote the Object documentation here, because I think it has some great explanations. I encourage you to read it, and also the documentation for these methods as they’re overridden in other classes, like String. Side note: if you want to try these out for yourself on different objects, use something like … Read more
JavaScript is very flexible with regards to checking for “null” values. I’m guessing you’re actually looking for empty strings, in which case this simpler code will work: if(!pass || !cpass || !email || !cemail || !user){ Which will check for empty strings (“”), null, undefined, false and the numbers 0 and NaN. Please note that … Read more
= is always assignment. Equality comparison is == (loose, coerces types to try to make a match) or === (no type coercion). So you want if (str === ”){ // —–^^^ not // NOT THIS if (str=””){ // —–^ What happens when you do if (str=””) is that the assignment str=”” is done, and then … Read more
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
You should implement the method __eq__: class MyClass: def __init__(self, foo, bar): self.foo = foo self.bar = bar def __eq__(self, other): if not isinstance(other, MyClass): # don’t attempt to compare against unrelated types return NotImplemented return self.foo == other.foo and self.bar == other.bar Now it outputs: >>> x == y True Note that implementing __eq__ … Read more
Because argv[1] (for instance) is actually a pointer to the string. So all you’re doing is comparing pointers.
It turns out Microsoft already has this covered in its testing framework: CollectionAssert.AreEquivalent Remarks Two collections are equivalent if they have the same elements in the same quantity, but in any order. Elements are equal if their values are equal, not if they refer to the same object. Using reflector, I modified the code behind … 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
the correct way to test floats for ‘equality’ is: if(Math.abs(sectionID – currentSectionID) < epsilon) where epsilon is a very small number like 0.00000001, depending on the desired precision.
= is the assignment operator. It sets a variable (the left-hand side) to a value (the right-hand side). The result is the value on the right-hand side. == is the comparison operator. It will only return true if both values are equivalent after coercing their types to the same type. === is a more strict … Read more