如何在C ++中向数组的末尾添加元素

Question

How to add element to last of array in c++?

int a[100] = {4,5}

How to add 6 to a[], then add 7 to a[]?

Answer 1

Looks like, as mentioned in the comments, you're looking for a std::vector :

std::vector<int> a{4, 5};
a.push_back(6); // a now {4, 5, 6}
a.push_back(7); // a now {4, 5, 6, 7}

Answer 2

You have an array of 100 elements initialized by an initializer list {4, 5} . This means a[0] is initialized to 4 , a[1] is initialized to 5 and all other array elements are initialized to 0 . Just because there are two elements in the initializer list doesn't mean there is an end of array after the second element. There are 98 more array elements, all set to the value of 0 . Your array size is fixed. It's 100 elements. If you want a container that dynamically changes its size, use std::vector instead.

Answer 3

您使用固定大小的C样式数组，因此只需替换下一个索引的值-或使用动态大小的std::vector （ https://en.cppreference.com/w/cpp/container/向量 ）