In this C++ tutorial, you will learn about vector::at() function, its syntax, and how to use this function to get the element at specific index, with example programs.
C++ Vector at() function
vector::at() function returns the reference to element at specified index/position in the vector.
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Examples
In the following examples, we will learn how to get reference to the element at given index in a vector.
1. Get element at index = 5 in string vector
In the following C++ program, we define a vector of integers, and get the reference to the element at index=5.
main.cpp
#include <iostream> #include <vector> using namespace std; int main() { vector<int> nums{ 1, 2, 4, 8, 16, 32, 64 }; int &x = nums.at( 5 ); cout << "Element at index=5 is " << x << endl; }
Output
Element at index=5 is 32
2. Get element at index = 2 in string vector
In the following C++ program, we define a vector of integers, and get the reference to the element at index=2.
main.cpp
#include <iostream> #include <vector> using namespace std; int main() { vector<string> arr{ "apple", "banana", "cherry", "mango" }; string &x = arr.at( 2 ); cout << "Element at index=2 is " << x << endl; }
Output
Element at index=2 is cherry
Conclusion
In this C++ Tutorial, we learned how to get reference to element at specific index of a vector using at() function.