How to Initialize a Vector in C++ - Step by Step Examples

How to Initialize a Vector in C++ ?

Answer

To initialize a vector in C++, you can use the std::vector class from the Standard Template Library (STL), which allows you to create dynamic arrays.

✐ Examples

1 Initialize a Vector of Integers

In this example,

We include the header to use the std::vector class.
We create a vector of integers using std::vector and provide a list of initial values enclosed in curly braces.
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() {
    std::vector<int> int_vector = {1, 2, 3, 4, 5};
    for (int num : int_vector) {
        std::cout << num << " ";
    }
    return 0;
}

Output

1 2 3 4 5

2 Initialize a Vector of Strings

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 a list of initial values enclosed in curly braces.
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() {
    std::vector<std::string> str_vector = {"apple", "banana", "cherry"};
    for (const std::string& str : str_vector) {
        std::cout << str << " ";
    }
    return 0;
}

Output

apple banana cherry

3 Initialize a Vector of Booleans

In this example,

We include the header to use the std::vector class.
We create a vector of booleans using std::vector and provide a list of initial values enclosed in curly braces.
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() {
    std::vector<bool> bool_vector = {true, false, true};
    for (bool val : bool_vector) {
        std::cout << std::boolalpha << val << " ";
    }
    return 0;
}

Output

true false true

Summary

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

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How to Initialize a Vector in C++ - Step by Step Examples

How to Initialize a Vector in C++ ?

Answer

✐ Examples

1 Initialize a Vector of Integers

C++ Program

Output

2 Initialize a Vector of Strings

C++ Program

Output

3 Initialize a Vector of Booleans

C++ Program

Output

Summary

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