The all_any_none_of function in c++ | STL

In this article, we'll see how to use all_of, any_of and none_of function in c++.

You must include the header bits/stdc++.h

Table of contents

• all_of

  • Code

  • Code

• any_of

  • Code

  • Code

• none_of

  • Code

  • Code

• References

• Thank You ❤️

---

all_of

all_of the function returns true if all of the elements of the given input array/vector passes the test.

For example, you want to check if the array contains all even numbers or not. For that, you can use the function like below.

Code

int main() {
    vector<int> v{4, 6, 8, 10};

    if (all_of(v.begin(), v.end(), [](int num) { return num % 2 == 0; })) {
        cout << "All numbers are even";
    } else {
        cout << "All numbers are not even";
    }
    return 0;
}

output

All numbers are even

The third argument is a lambda function, which will check if the current element is even or odd.

Code

int main() {
    vector<int> v{4, 6, 8, 10,15};

    if (all_of(v.begin(), v.end(), [](int num) { return num % 2 == 0; })) {
        cout << "All numbers are even";
    } else {
        cout << "All numbers are not even";
    }
    return 0;
}

output

All numbers are not even

---

any_of

any_of function is used to check if any of the elements of the array passes the test or not.

Code

int main() {
    vector<int> v{1,5,8,7};

    if (any_of(v.begin(), v.end(), [](int num) { return num % 2 == 0; })) {
        cout << "A number of the array is even";
    } else {
        cout << "There is no even numbers in the array";
    }
    return 0;
}

Output

A number of the array is even

Code

int main() {
    vector<int> v{1,5,81,7};

    if (any_of(v.begin(), v.end(), [](int num) { return num % 2 == 0; })) {
        cout << "A number of the array is even";
    } else {
        cout << "There is no even numbers in the array";
    }
    return 0;
}

Output

There is no even numbers in the array

---

none_of

none_of the function returns true if none of the elements passes the test.

Code

int main() {
    vector<int> v{4, 61, 8};

    if (none_of(v.begin(), v.end(), [](int num) { return num % 2 == 0; })) {
        cout << "None of the numbers is even";
    } else {
        cout << "There are some even numbers";
    }
    return 0;
}

O/P

There are some even numbers

Code

int main() {
    vector<int> v{41, 61, 81};

    if (none_of(v.begin(), v.end(), [](int num) { return num % 2 == 0; })) {
        cout << "None of the numbers is even";
    } else {
        cout << "There are some even numbers";
    }
    return 0;
}

O/P

None of the numbers is even

References

• all_any_none_of

• comparator function

• lambda

Thank You ❤️