Batch not-equal (inequality) operator
Try if NOT “asdf” == “fdas” echo asdf
operators
What is x after “x = x++”?
x = x++; is equivalent to int tmp = x; x++; x = tmp;
Use of “instanceof” in Java [duplicate]
Basically, you check if an object is an instance of a specific class. You normally use it, when you have a reference or parameter to an object that is of a super class or interface type and need to know whether the actual object has some other type (normally more concrete). Example: public void doSomething(Number … Read more
What does the ^ operator do in Java?
The ^ operator in Java ^ in Java is the exclusive-or (“xor”) operator. Let’s take 5^6 as example: (decimal) (binary) 5 = 101 6 = 110 —————— xor 3 = 011 This the truth table for bitwise (JLS 15.22.1) and logical (JLS 15.22.2) xor: ^ | 0 1 ^ | F T –+—– –+—– 0 … Read more
Python != operation vs “is not”
== is an equality test. It checks whether the right hand side and the left hand side are equal objects (according to their __eq__ or __cmp__ methods.) is is an identity test. It checks whether the right hand side and the left hand side are the very same object. No methodcalls are done, objects can’t … Read more
How can I obtain the element-wise logical NOT of a pandas Series?
To invert a boolean Series, use ~s: In [7]: s = pd.Series([True, True, False, True]) In [8]: ~s Out[8]: 0 False 1 False 2 True 3 False dtype: bool Using Python2.7, NumPy 1.8.0, Pandas 0.13.1: In [119]: s = pd.Series([True, True, False, True]*10000) In [10]: %timeit np.invert(s) 10000 loops, best of 3: 91.8 µs per … Read more
‘AND’ vs ‘&&’ as operator
If you use AND and OR, you’ll eventually get tripped up by something like this: $this_one = true; $that = false; $truthiness = $this_one and $that; Want to guess what $truthiness equals? If you said false… bzzzt, sorry, wrong! $truthiness above has the value true. Why? = has a higher precedence than and. The addition … Read more
What does “|=” mean? (pipe equal operator)
|= reads the same way as +=. notification.defaults |= Notification.DEFAULT_SOUND; is the same as notification.defaults = notification.defaults | Notification.DEFAULT_SOUND; where | is the bit-wise OR operator. All operators are referenced here. A bit-wise operator is used because, as is frequent, those constants enable an int to carry flags. If you look at those constants, you’ll … Read more
Why don’t C++ compilers define operator== and operator!=?
The argument that if the compiler can provide a default copy constructor, it should be able to provide a similar default operator==() makes a certain amount of sense. I think that the reason for the decision not to provide a compiler-generated default for this operator can be guessed by what Stroustrup said about the default … Read more
What is the instanceof operator in JavaScript?
instanceof The Left Hand Side (LHS) operand is the actual object being tested to the Right Hand Side (RHS) operand which is the actual constructor of a class. The basic definition is: Checks the current object and returns true if the object is of the specified object type. Here are some good examples and here … Read more