How to create a Vector of Size N in C++ - Step by Step Examples

How to create a Vector of Size N in C++ ?

Answer

To create a vector of size N in C++, you can use the std::vector class from the Standard Template Library (STL) and initialize it with a specific size and optional default value.

✐ Examples

1 Create a Vector of Integers of Size N

In this example,

We include the header to use the std::vector class.
We create a vector of integers using std::vector and provide the size n as an argument to the constructor. This initializes the vector with n elements, each set to 0 by default.
The vector is then assigned to a variable named int_vector.
Finally, we use a range-based for loop to iterate over the vector and print each element.

C++ Program

#include <iostream>
#include <vector>

int main() {
    size_t n = 5;
    std::vector<int> int_vector(n);
    for (int num : int_vector) {
        std::cout << num << " ";
    }
    return 0;
}

Output

0 0 0 0 0

2 Create a Vector of Strings of Size N

In this example,

We include the and headers to use the std::vector and std::string classes.
We create a vector of strings using std::vector and provide the size n as an argument to the constructor. This initializes the vector with n elements, each set to an empty string "" by default.
The vector is then assigned to a variable named str_vector.
Finally, we use a range-based for loop to iterate over the vector and print each element.

C++ Program

#include <iostream>
#include <vector>
#include <string>

int main() {
    size_t n = 5;
    std::vector<std::string> str_vector(n);
    for (const std::string& str : str_vector) {
        std::cout << '"' << str << '"' << " ";
    }
    return 0;
}

Output

"" "" "" "" ""

3 Create a Vector of Booleans of Size N

In this example,

We include the header to use the std::vector class.
We create a vector of booleans using std::vector and provide the size n as an argument to the constructor. This initializes the vector with n elements, each set to false by default.
The vector is then assigned to a variable named bool_vector.
Finally, we use a range-based for loop to iterate over the vector and print each element.

C++ Program

#include <iostream>
#include <vector>

int main() {
    size_t n = 5;
    std::vector<bool> bool_vector(n);
    for (bool val : bool_vector) {
        std::cout << std::boolalpha << val << " ";
    }
    return 0;
}

Output

false false false false false

Summary

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

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How to create a Vector of Size N in C++ - Step by Step Examples

How to create a Vector of Size N in C++ ?

Answer

✐ Examples

1 Create a Vector of Integers of Size N

C++ Program

Output

2 Create a Vector of Strings of Size N

C++ Program

Output

3 Create a Vector of Booleans of Size N

C++ Program

Output

Summary

More C++ Vectors Tutorials