C++ Algorithm Function any_of()

C++ Algorithm any_of() function tests the value of 'pred' for every element in the range, if for any element the value of pred is true, then the function returns true else return false.

Syntax

template <class InputIteratir, class UnaryPredicate>
bool any_of (InputIterator first, InputIterator last, UnaryPredicate pred);

Parameter

first: It is the first element in the range specified.

last: It is the last element in the range.

pred: It is a unary function which accepts the argument from the range.

Return value

The function has one return type, 'true'. If the value of argument 'pred' is true for any of the elements of the range then the value 'true' is returned, else false.

Example 1

#include <iostream>
#include <algorithm>
#include <array>
using namespace std;
int main()
{
	int arr[7] = {2,4,6,5,10,3,14};
	any_of(arr,arr+6, [](int k){return k%2;})?
	cout <<"There are elements which exist in the table of 2":
	cout<<"No elements in the table of 2 exists";
	return 0;
}

Output:

There are elements which exist in the table of 2.

Example 2

#include <iostream>
#include <algorithm>
#include <array>
int main()
{
	std::array<int, 5> arr = {2,-4,6,-9,10};
	if(std::any_of (arr.begin(), arr.end(), [](int k) { return k<0;}))
	std::cout <<"Negative elements exist in the array";
	return 0;
}

Output:

Negative elements exist in the array

Complexity

The function moves linearly, starting from the first element going towards the last one. For each element of the list, the value of 'pred' is checked. The search goes on until a mismatch for the 'pred' value is encountered.