What does the >?= operator mean?
It’s a GCC extension that was removed in GCC version 4.2 and later. The equivalent of a >?= b is a = max(a,b); There is also a very similar operator a <?= b which means the same as a = min(a, b);.
operators
Logical operator && and two strings in javascript
in the expression “Cat” && “Dog” // => “Dog” Because you’re using &&, JavaScript is promising you that it will verify that both sides of the expression are true. In this case, “Dog” is the just the last evaluated thing. To be more explicit, you could do something like var c = “Cat” != null … Read more
Python a &= b meaning?
What does a &= b mean? This depends on the implementation for the types of a and b, but semantics are essentially that a &= b is the update of a with its “AND” for b. That “AND” operation could be a set intersection, a binary AND operation, or some other operation that can be … Read more
and / or operators return value [duplicate]
The and and or operators do return one of their operands, not a pure boolean value like True or False: >>> 0 or 42 42 >>> 0 and 42 0 Whereas not always returns a pure boolean value: >>> not 0 True >>> not 42 False
What does the comma operator do?
Comma operator is applied and the value 5 is used to determine the conditional’s true/false. It will execute blah() and get something back (presumably), then the comma operator is employed and 5 will be the only thing that is used to determine the true/false value for the expression. Note that the , operator could be … Read more
Prolog =:= operator
I think the above answer deserves a few words of explanation here nevertheless. A short note in advance: Arithmetic expressions in Prolog are just terms (“Everything is a term in Prolog”), which are not evaluated automatically. (If you have a Lisp background, think of quoted lists). So 3 + 4 is just the same as … Read more
How >> operator defines task dependencies in Airflow?
Airflow represents workflows as directed acyclic graphs. A workflow is any number of tasks that have to be executed, either in parallel or sequentially. The “>>” is Airflow syntax for setting a task downstream of another. Diving into the incubator-airflow project repo, models.py in the airflow directory defines the behavior of much of the high … Read more
What does the question mark mean in GSP/Grails?
It’s the “Safe Navigation Operator”, which is a Groovy feature that concisely avoids null pointer exceptions. See http://docs.groovy-lang.org/latest/html/documentation/index.html#_safe_navigation_operator In this case, if phoneInstance is null, then it doesn’t try to get the name property and cause a NPE – it just sets the value of the field tag to null.
Why does C++ need the scope resolution operator?
Because someone in the C++ standards committee thought that it was a good idea to allow this code to work: struct foo { int blah; }; struct thingy { int data; }; struct bar : public foo { thingy foo; }; int main() { bar test; test.foo.data = 5; test.foo::blah = 10; return 0; } … Read more