How to Filter Elements of an Array based on a Condition in C++ - Step by Step Examples

How to Filter Elements of an Array based on a Condition in C++ ?

Answer

To filter elements of an array based on a condition in C++, you can use standard algorithms like std::copy_if or std::remove_if.

✐ Examples

1 Filter Even Numbers

In this example,

We have an array named numbers containing integers.
We use std::copy_if algorithm with a lambda function to filter out even numbers into a new array named evenNumbers.
We print the filtered array to demonstrate the filtering.

C++ Program

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main() {
    vector<int> numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    vector<int> evenNumbers;
    std::copy_if(numbers.begin(), numbers.end(), std::back_inserter(evenNumbers), [](int num){ return num % 2 == 0; });
    cout << "Even Numbers: ";
    for (int num : evenNumbers) {
        cout << num << " ";
    }
    return 0;
}

Output

Even Numbers: 2 4 6 8 10

2 Filter Strings by Length

In this example,

We have a vector named words containing strings.
We use std::copy_if algorithm with a lambda function to filter strings by their length into a new vector named filteredWords.
We print the filtered vector to demonstrate the filtering.

C++ Program

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
int main() {
    vector<string> words = {"apple", "banana", "cherry", "date", "fig"};
    vector<string> filteredWords;
    std::copy_if(words.begin(), words.end(), std::back_inserter(filteredWords), [](const string& word){ return word.length() > 5; });
    cout << "Filtered Words: ";
    for (const string& word : filteredWords) {
        cout << word << " ";
    }
    return 0;
}

Output

Filtered Words: banana cherry

Summary

In this tutorial, we learned How to Filter Elements of an Array based on a Condition in C++ language with well detailed examples.

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How to Filter Elements of an Array based on a Condition in C++ - Step by Step Examples

How to Filter Elements of an Array based on a Condition in C++ ?

Answer

✐ Examples

1 Filter Even Numbers

C++ Program

Output

2 Filter Strings by Length

C++ Program

Output

Summary

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