assignment-operator

问题 I have a long set of comparisons to do in Java, and I'd like to know if one or more of them come out as true. The string of comparisons was long and difficult to read, so I broke it up for readability, and automatically went to use a shortcut operator |= rather than negativeValue = negativeValue || boolean . boolean negativeValue = false; negativeValue |= (defaultStock < 0); negativeValue |= (defaultWholesale < 0); negativeValue |= (defaultRetail < 0); negativeValue |= (defaultDelivery < 0);

问题 I have a long set of comparisons to do in Java, and I'd like to know if one or more of them come out as true. The string of comparisons was long and difficult to read, so I broke it up for readability, and automatically went to use a shortcut operator |= rather than negativeValue = negativeValue || boolean . boolean negativeValue = false; negativeValue |= (defaultStock < 0); negativeValue |= (defaultWholesale < 0); negativeValue |= (defaultRetail < 0); negativeValue |= (defaultDelivery < 0);

问题 class phone { public: phone(int x) { num = x; } int number(void) { return num; } void number(int x) { num = x; } private: int num; }; int main(void) { phone p1(10); p1 = 20; // here! return 0; } Hi, guys Just I declared a simple class like above one. After that I assigned int value to the object that class, then it worked! (I printed its value. It was stored properly) If there is not a construct with int parameter, a compile error occurred. So, I think it's related with a constructor. Is that

问题 class phone { public: phone(int x) { num = x; } int number(void) { return num; } void number(int x) { num = x; } private: int num; }; int main(void) { phone p1(10); p1 = 20; // here! return 0; } Hi, guys Just I declared a simple class like above one. After that I assigned int value to the object that class, then it worked! (I printed its value. It was stored properly) If there is not a construct with int parameter, a compile error occurred. So, I think it's related with a constructor. Is that

问题 This question already has an answer here : Assignment associativity [duplicate] (1 answer) Closed 3 years ago . Can anyone tell how the output became undefined ? var foo = {n: 2}; foo.x = foo = {n: 2}; console.log(foo.x); // undefined 回答1: foo.x = foo = {n:2}; The foo.x refers to the property x to the object refered to by foo . However, foo = {n:2} assigns a completely new object to foo . x is indeed assigned to an object, but that object is immediately replaced by another object. The object

问题 A "Singular Iterator" is defined as an: iterators that are not associated with any sequence. A null pointer, as well as a default-constructed pointer (holding an indeterminate value) is singular My question 1 would be: Is a default constructed iterator considered a "Singular Iterator"? Secondly, I have been told here that: Results of most expressions are undefined for singular values; the only exceptions are destroying an iterator that holds a singular value, the assignment of a non-singular

问题 Can someone justify the need of privatizing the assignment operator in a Singleton class implementation? What problem does it solve by making Singleton& operator=(Singleton const&); private? class Singleton { public: static Singleton& Instance() { static Singleton theSingleton; return theSingleton; } private: Singleton(); // ctor hidden Singleton(Singleton const&); // copy ctor hidden Singleton& operator=(Singleton const&); // assign op. hidden ~Singleton(); // dtor hidden }; 回答1: Assignment

问题 Can someone justify the need of privatizing the assignment operator in a Singleton class implementation? What problem does it solve by making Singleton& operator=(Singleton const&); private? class Singleton { public: static Singleton& Instance() { static Singleton theSingleton; return theSingleton; } private: Singleton(); // ctor hidden Singleton(Singleton const&); // copy ctor hidden Singleton& operator=(Singleton const&); // assign op. hidden ~Singleton(); // dtor hidden }; 回答1: Assignment

问题 Can someone justify the need of privatizing the assignment operator in a Singleton class implementation? What problem does it solve by making Singleton& operator=(Singleton const&); private? class Singleton { public: static Singleton& Instance() { static Singleton theSingleton; return theSingleton; } private: Singleton(); // ctor hidden Singleton(Singleton const&); // copy ctor hidden Singleton& operator=(Singleton const&); // assign op. hidden ~Singleton(); // dtor hidden }; 回答1: Assignment

问题 Let's just take for example the specific compound assignment operator ^= . This stackoverflow page says modification of the left operand may have not been done after the evaluation of ^= , and thus making the code a ^= b ^= a ^= b undefined behaivor. But this does not seem to be the case. The standard says in 5.17 [expr.ass] that In all cases, the assignment is sequenced after the value computation of the right and left operands, and before the value computation of the assignment expression.