Check out example codes for "find_if c++ example". It will help you in understanding the concepts better.

Code Example 1

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
  vector<int> myvec {2, 5, 6, 10, 56, 7, 48, 89};
  vector<int>::iterator gt10 = find_if(myvec.begin(), myvec.end(), [](int x){return x>10;}); // >= C++11
  cout << "First item >   10: " << *gt10  << endl;
  
    //check if pointer points to myvec.end()
  if(gt10 != myvec.end()) {
    cout << "nf points to: " << *gt10 << endl;
  }
  else {
    cout << "item not found" << endl;
  }

  return 0;
}

Code Example 2

InputIterator find_if (InputIterator first, InputIterator last, UnaryPredicate pred);

first, last :range which contains all the elements between first
and last, including the element pointed by first but
not the element pointed by last.

pred : Unary function that accepts an element in the range
as argument and returns a value in boolean.

Return value :
Returns an iterator to the first element in the range
[first, last] for which pred(function) returns true. If
no such element is found, the function returns last.

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