C++ <array> - operator< Function

The C++ <array> operator< function is used to check whether the first array is less than the second array or not. It returns true if the first array is less than the second array, else returns false. operator< compares elements of arrays sequentially and stops comparison after first mismatch.

Syntax

• C++11

template <class T, size_T N>
bool operator< (const array<T,N>& lhs, const array<T,N>& rhs);

Parameters

Return Value

Returns true if the contents of lhs are lexicographically less than the contents of rhs, else returns false.

Time Complexity

Linear i.e, Θ(n).

Example:

In the example below, the operator< function is used to check whether the first array is less than the second array or not.

#include <iostream>
#include <array>
using namespace std;
 
int main (){
  array<int, 3> arr1 {10, 20, 30};
  array<int, 3> arr2 {10, 20, 30};
  array<int, 3> arr3 {40, 50, 60};

  if (arr1 < arr2)
    cout<<"arr1 is less than arr2.\n";
  else
    cout<<"arr1 is not less than arr2.\n";

  if (arr1 < arr3)
    cout<<"arr1 is less than arr3.\n";
  else
    cout<<"arr1 is not less than arr3.\n";
    
  return 0;
}

The output of the above code will be:

arr1 is not less than arr2.
arr1 is less than arr3.