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Count occurrences of value in a range

123456789101112# include <iostream> # include <algorithm> # include <vector> int main() { std::vector<int> numbers = {1, 2, 3, 5, 6, 3, 4, 1}; int count = std::count(std::begin(numbers), std::end(numbers), 3); }

This pattern is licensed under the CC0 Public Domain Dedication.

Requires c++98 or newer.

Intent

Count the number of occurrences of a particular value in a range of elements.

Description

On line 7, we create a std::vector of int initialized with some values.

On lines 9–11, we use the alrogithm std::count, to count the occurrences of a particular value in the std::vector. For the first two arguments on lines 9–10, we use std::begin and std::end to get the begin and end iterators for the range in which we wish to count. The third argument on line 11 is the value to count the occurrences of.

To count elements according to a predicate, you can use std::count_if instead.

Contributors

  • Joseph Mansfield
  • Jatin Dhankhar

Last Updated

09 December 2017

Source

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