tldr; Although both var++ and ++var increment the variable they are applied to, the result returned by var++ is the value of the variable before incrementing, whereas the result returned by ++var is the value of the variable after the increment is applied. Further Explanation When ++var or var++ form a complete statement (as in … Read more
This is certainly going to make it easier to write a correct operator than rolling it yourself. I’d say only consider a different approach if profiling shows the comparison operation to be a time-consuming part of your application. Otherwise the ease of maintaining this should outweigh any possible performance concerns.
They always give the same result. In fact, not ‘ham’ in ‘spam and eggs’ appears to be special cased to perform a single “not in” operation, rather than an “in” operation and then negating the result: >>> import dis >>> def notin(): ‘ham’ not in ‘spam and eggs’ >>> dis.dis(notin) 2 0 LOAD_CONST 1 (‘ham’) … Read more
AND operation a=$(‘[myc=”blue”][myid=”1″][myid=”3″]’); OR operation, use commas a=$(‘[myc=”blue”],[myid=”1″],[myid=”3″]’); As @Vega commented: a=$(‘[myc=”blue”][myid=”1″],[myc=”blue”][myid=”3″]’);
When you write 1 << n You shift the bit combination 000000001 for n times left and thus put n into the exponent of 2: 2^n So 1 << 10 Really is 1024 For a list of say 5 items your for will cycle 32 times.
There is no “better” but the more common one is ||. They have different precedence and || would work like one would expect normally. See also: Logical operators (the following example is taken from there): // The result of the expression (false || true) is assigned to $e // Acts like: ($e = (false || … Read more
concat and spreads are very different when the argument is not an array. When the argument is not an array, concat adds it as a whole, while … tries to iterate it and fails if it can’t. Consider: a = [1, 2, 3] x = ‘hello’; console.log(a.concat(x)); // [ 1, 2, 3, ‘hello’ ] console.log([…a, … Read more
It’s called the “Non-null assertion operator” and it tells the compiler that x.getY() is not null. It’s a new typescript 2.0 feature and you can read about it in the what’s new page, here’s what it says: A new ! post-fix expression operator may be used to assert that its operand is non-null and non-undefined … Read more
It’s not deprecated and is unlikely to be. It’s the standard way to, for example, make part of one array or object mirror changes made to another, instead of copying the existing data. It’s called assignment by reference, which, to quote the manual, “means that both variables end up pointing at the same data, and … Read more
Python, should I implement __ne__() operator based on __eq__? Short Answer: Don’t implement it, but if you must, use ==, not __eq__ In Python 3, != is the negation of == by default, so you are not even required to write a __ne__, and the documentation is no longer opinionated on writing one. Generally speaking, … Read more