How to Get Length of a Vector in C++ - Step by Step Examples

How to Get Length of a Vector in C++ ?

Answer

To get the length of a vector in C++, you can use the size method of the std::vector class from the Standard Template Library (STL).

✐ Examples

1 Get Length of a Numeric Vector

In this example,

We include the header to use the std::vector class and the header to use input/output streams.
We create a vector named num_vector that holds integers using the std::vector declaration.
We initialize num_vector with a set of numeric values using an initializer list {10, 20, 30, 40, 50}.
We call the size method on num_vector to get the number of elements in the vector. The size method returns the length of the vector as a size_t value.
We assign the result of the size method to a variable named num_vector_length.
Finally, we print the length of the vector using std::cout to display the value of num_vector_length on the console.

C++ Program

#include <vector>
#include <iostream>

int main() {
    std::vector<int> num_vector = {10, 20, 30, 40, 50};
    std::size_t num_vector_length = num_vector.size();
    std::cout << "Length of numeric vector: " << num_vector_length << std::endl;
    return 0;
}

Output

Length of numeric vector: 5

2 Get Length of a String Vector

In this example,

We include the header to use the std::vector class and the header to use input/output streams.
We create a vector named str_vector that holds strings using the std::vector declaration.
We initialize str_vector with a set of string values using an initializer list {"apple", "banana", "cherry"}.
We call the size method on str_vector to get the number of elements in the vector. The size method returns the length of the vector as a size_t value.
We assign the result of the size method to a variable named str_vector_length.
Finally, we print the length of the vector using std::cout to display the value of str_vector_length on the console.

C++ Program

#include <vector>
#include <iostream>

int main() {
    std::vector<std::string> str_vector = {"apple", "banana", "cherry"};
    std::size_t str_vector_length = str_vector.size();
    std::cout << "Length of string vector: " << str_vector_length << std::endl;
    return 0;
}

Output

Length of string vector: 3

Summary

In this tutorial, we learned How to Get Length of a Vector in C++ language with well detailed examples.

◀ Previous Next ▶