You’re missing a key exception to the usual behaviour: when the right-hand operand is an instance of a subclass of the class of the left-hand operand, the special method for the right-hand operand is called first. See the documentation at: http://docs.python.org/reference/datamodel.html#coercion-rules and in particular, the following two paragraphs: For objects x and y, first x.__op__(y) … Read more
s1 == “” is not reliable as it tests reference equality not object equality (and String isn’t strictly canonical). s1.equals(“”) is better but can suffer from null pointer exceptions. Better yet is: “”.equals(s1) No null pointer exceptions. EDIT: Ok, the point was asked about canonical form. This article defines it as: Suppose we have some … Read more
Simply use : mapA.equals(mapB); Compares the specified object with this map for equality. Returns true if the given object is also a map and the two maps represent the same mappings
You can’t accidently assign null to obj by typing obj = null instead. However, that’s a reminiscence from C times, in java, it is not possible, as the = expression returns the right hand side of the assignment. As null is not a boolean, the compiler will complain. I would try to explain it to … Read more
You can use javascript’s indexOf function. var str1 = “ABCDEFGHIJKLMNOP”; var str2 = “DEFG”; if(str1.indexOf(str2) != -1){ console.log(str2 + ” found”); }
In Python, the == operator is implemented in terms of the magic method __eq__, which by default implements it by identity comparison. You can, however, override the method in order to provide your own concept of object equality. Note, that if you do so, you will usually also override at least __ne__ (which implements the … Read more
There are already many questions asked on SO for comparisons between HTML5 and Flash. HTML5 by itself isn’t powerful enough (being a markup language), but people commonly refer to the whole stack that is HTML5, Javascript, CSS3 and more when referring to HTML5. This is not the tabular comparison that you were looking for, but … Read more
You haven’t specified a platform, but I’m guessing .NET. I would strongly suggest you use the latter form – because case comparisons aren’t as simple as you might expect. (It also avoids creating extra strings, but that’s a different matter.) For example, what do you want your code to do when presented with “mail” and … Read more
Quoting the doc (MDN): Equal (==) If the two operands are not of the same type, JavaScript converts the operands then applies strict comparison. If either operand is a number or a boolean, the operands are converted to numbers if possible; else if either operand is a string, the other operand is converted to a … Read more
There are various different ways of doing this. Have a look at the Wikipedia “String similarity measures” page for links to other pages with algorithms. I don’t think any of those algorithms take sounds into consideration, however – so “staq overflow” would be as similar to “stack overflow” as “staw overflow” despite the first being … Read more