No, |= and &= do not shortcircuit, because they are the compound assignment version of & and |, which do not shortcircuit. JLS 15.26.2 Compound Assignment Operators A compound assignment expression of the form E1 op= E2 is equivalent to E1 = (T)((E1) op (E2)), where T is the type of E1, except that E1 … Read more
Since your condition is falsy and so doesn’t return the second argument (<GeneralLoader />), it will return profileTypesLoading, which is a number, so react will render it because React skips rendering for anything that is typeof boolean or undefined and will render anything that is typeof string or number: To make it safe, you can … Read more
This is called short-circuit evaluation. It is generally true for languages derived from C (C, C++, Java, C#) but not true for all languages. For example, VB6 does not do this, nor was it done in early versions of VB.NET. VB8 (in Visual studio 2005) introduced the AndAlso and OrElse operators for this purpose. Also, … Read more
Your reasoning is correct. There is an unamb package providing tools for the sort of parallel computation you refer to. In fact, it offers Data.Unamb.pmult, which tries, in parallel, to check whether each operand is 1 or 0, and if so immediately produces a result. This parallel approach is likely to be much slower in … Read more
The && and || operators short-circuit. That is: 1) If && evaluates its first operand as false, it does not evaluate its second operand. 2) If || evaluates its first operand as true, it does not evaluate its second operand. This lets you do null check && do something with object, as if it is … Read more
The behaviour is guaranteed. I’ve contributed a patch, which was accepted and merged recently, so if you grab the latest sources you will see that the short-circuiting behaviour is now explicitly enforced. git clone https://github.com/python/cpython.git grep Short-circuit cpython/Lib/test/test_builtin.py
The wikipedia page is wrong, I’ve corrected it. | and & are not boolean operators, even though they are eager operators, which just means that they are not short circuit operators. As you probably know, here’s how the python and and or operators work: >>> def talk(x): … print “Evaluating: “, bool(x) … return x … Read more
Yes, the && operator in C++ uses short-circuit evaluation so that if bool1 evaluates to false it doesn’t bother evaluating bool2. “Short-circuit evaluation” is the fancy term that you want to Google and look for in indexes. The same happens with the || operator, if bool1 evaluates to true then the whole expression will evaluate … Read more
From C++11 5.17 Assignment and compound assignment operators: The behavior of an expression of the form E1 op = E2 is equivalent to E1 = E1 op E2 except that E1 is evaluated only once. However, you’re mixing up logical AND which does short-circuit, and the bitwise AND which never does. The text snippet &&=, … Read more
Yes. In C# && and || are short-circuiting and thus evaluates the right side only if the left side doesn’t already determine the result. The operators & and | on the other hand don’t short-circuit and always evaluate both sides. The spec says: The && and || operators are called the conditional logical operators. They … Read more