vector.erase()删除iterator后,会传回下一个iterator的pointer,若在由for loop的++iter,则会少考虑了被删除后的下一个iterator,故需加上--,将iterator往前移,移到被删除的iterator的前一个iterator,这样for loop的++iterator才会考虑到被删除的下一个iterator。 为了证明这个方法可行,而不是只适用于vector(因为常发...
初学者若想要删除std::vector内的element,第一个想到的就是用for loop,若该iterator的值是我要删的,就erase 1 // Compile OK, but run-time error!! 2 for(std::vector<int>::iterator iter = ivec.begin(); iter != ivec.end(); ++iter) { 3 if (*iter == 8) { 4 ivec.erase(iter); ...
#include <iostream> #include <vector> int main() { std::vector<int> vec = {1, 2, 3, 4, 5}; // 使用传统的 for 循环遍历 std::cout << "Using traditional for loop:" << std::endl; for (size_t i = 0; i < vec.size(); ++i) { ...
end(); ++it) { std::cout << " " << *it; } std::cout << std::endl; // 使用范围-based for 循环遍历 vector 容器并打印每个元素 std::cout << "Elements in vector (using range-based for loop):"; for (int num : vec) { std::cout << " " << num; } std::cout << std:...
}// for loopfor(constauto& cb : lifecycleObservers_) { cb->connect(this); }// iterator / eraseconstautoeraseIt = std::remove( lifecycleObservers_.begin(), lifecycleObservers_.end(), observer);if(eraseIt == lifecycleObservers_.end()) {returnfalse; ...
The trick is to use while loop instead of // for loop while(it != v.end()) { bool shouldDelete = TestIfDeletion(*it); if(shouldDelete) { it = v.erase(it); // Now "it" pointed to next value in vector (possibly 'end') } else { it++; } }...
void testCopyLoop() { cout << "copy loop" << endl; { auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count(); QList<QSharedPointer<Test>> list2; list2.resize(END - START + 1); for (int i = START; i < END; ++i) { ...
You will notice that in this for loop // I have left out the initialisation section; this is // because it has been done separatly before. for(; itNum < arNumbers.end(); itNum++) printf("Value at position %d is %d\n", (int)(itNum - arNumbers.begin()), *itNum); } In ...
for each object in the for-loop, get a value associated with it. 2. Here, I need to delete the entries in the vector which match the value returned above. } How do I ensure this?. Note that I might most likely need to delete data from the vector in different iterations of the ...
若要删除std::vector中的element,正规的方式该用find() generic algorithm,若find()找到了,会传回该iterator,若找不到,将传回vector.end()。这种写法远比用for loop干净很多。 1 /* 2 (C) OOMusou 2006http://oomusou.cnblogs.com 3 4 Filename : VectorFindAndErase.cpp ...