In this C++ tutorial, you shall learn about vector of vectors, how to create vector of vectors, and traverse the inner vectors using For loop, with example programs.
Vector of Vectors in C++
Vector of vectors is a vector in which each element is a vector of elements.
To create a vector of vectors, we need to specify the datatype of element as vector<>
, and specify vectors as elements, as shown in the following.
//int vectors vector<int> v1 { 1, 3, 5, 7, 9 }; vector<int> v2 { 2, 4, 6, 8, 10 }; //vector of vectors vector<vector<int>> vv = {v1, v2};
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Examples
1. Vector of Integer Vectors
In the following program, we take two integer vectors in v1
and v2
, and use them to create a vector of integer vectors vv
.
main.cpp
#include <iostream> #include <vector> using namespace std; int main() { //int vectors vector<int> v1 { 1, 3, 5, 7, 9 }; vector<int> v2 { 2, 4, 6, 8, 10 }; //vector of vectors vector<vector<int>> vv = {v1, v2}; //iterate over vector elements for (auto& tempVector : vv) { for (auto& element : tempVector) { cout << element << " "; } cout << endl; } }
Output
1 3 5 7 9 2 4 6 8 10
Conclusion
In this C++ Tutorial, we learned how to define a vector of vectors, and how to traverse through individual elements of the inner vectors.