sort vector struct c++

To sort a vector of structs in C++, you can follow these steps:

1. Include the necessary header files: In order to use the vector class and the sort algorithm, you need to include the and header files.

2. Define the struct: Define the struct that represents the elements stored in the vector. For example, if you want to sort a vector of persons, you can define a struct like this:

struct Person {
    std::string name;
    int age;
};

1. Create a vector of structs: Declare and initialize a vector of struct elements. For example:

std::vector<Person> persons = {{"John", 25}, {"Alice", 30}, {"Bob", 20}};

1. Define a comparison function: In order to sort the vector of structs, you need to define a comparison function. This function compares two struct elements and returns true if the first element should come before the second element in the sorted order. For example, if you want to sort the persons based on their age in ascending order, you can define a comparison function like this:

bool compareByAge(const Person& p1, const Person& p2) {
    return p1.age < p2.age;
}

1. Sort the vector: Use the std::sort function from the header to sort the vector. Pass the beginning and end iterators of the vector, as well as the comparison function as arguments. For example:

std::sort(persons.begin(), persons.end(), compareByAge);

After this step, the vector will be sorted based on the comparison function provided.

Note: You can also use a lambda function instead of defining a separate comparison function. For example:

std::sort(persons.begin(), persons.end(), [](const Person& p1, const Person& p2) {
    return p1.age < p2.age;
});

This lambda function performs the same comparison as the compareByAge function.

That's it! Now you have successfully sorted a vector of structs in C++.