# Relational Operators on STL Array in C++

The article illustrates the working of the different relational operator on the array STL. The equality comparison ( == ) is performed by comparing the elements sequentially using operator ( == ), stopping at the first mismatch.
The less-than comparison ( < ) or greater-than comparison ( > ) behaves as if using algorithm lexicographical_compare, which compares the elements sequentially using operator () in a reciprocal manner (i.e., checking both a<b and b<a) and stopping at the first occurrence.
The implementation of relational operators on the array help us to compare between the data stored in different arrays.

Equivalent operators : Here are some operators whose work is same.

```  (a != b) is equivalent to !(a == b)
(a > b) equivalent to (b < a)
(a <= b) equivalent to !(b < a)
```

Time Complexity : The time complexity of the above operation is O(n) where n is the size of the array.

Below is the code to illustrate the working of relational operators on array

Program 1: Relational Operator Comparison

 `// array comparisons using relational operators ` `#include ` `using` `namespace` `std; ` ` `  `int` `main() ` `{ ` `    ``// declaration of array ` `    ``array<``int``, 5> a = { 1, 2, 3, 4, 5 }; ` `    ``array<``int``, 5> b = { 1, 2, 3, 4, 5 }; ` `    ``array<``int``, 5> c = { 5, 4, 3, 2, 1 }; ` ` `  `    ``if` `(a >= b) { ` `        ``cout << ``"a is greater than equal to b\n"``; ` `    ``} ` `    ``else` `{ ` `        ``cout << ``"a is neither greater than nor equal to b\n"``; ` `    ``} ` ` `  `    ``if` `(b < c) { ` `        ``cout << ``"b is less than c\n"``; ` `    ``} ` `    ``else` `{ ` `        ``cout << ``"b is not lesser than c\n"``; ` `    ``} ` `    ``if` `(a >= c) { ` `        ``cout << ``"a is greater than equal to c\n"``; ` `    ``} ` `    ``else` `{ ` `        ``cout << ``"a is neither greater than nor equal to c\n"``; ` `    ``} ` ` `  `    ``return` `0; ` `} `

Output :

```a is greater than equal to b
b is less than c
a is neither greater than nor equal to c
```

Program 2: Relational Operator Equality

 `// CPP program to check for array qualities. ` `#include ` `using` `namespace` `std; ` ` `  `int` `main() ` `{ ` `    ``// declaration of array ` `    ``array<``char``, 5> a = { ``'a'``, ``'b'``, ``'c'``, ``'d'``, ``'e'` `}; ` `    ``array<``char``, 5> b = { ``'e'``, ``'d'``, ``'c'``, ``'b'``, ``'a'` `}; ` `    ``array<``char``, 5> c = { ``'a'``, ``'b'``, ``'c'``, ``'d'``, ``'e'` `}; ` ` `  `    ``if` `(a == b) { ` `        ``cout << ``"a is  equal to b\n"``; ` `    ``} ` `    ``else` `{ ` `        ``cout << ``"a is not equal to b\n"``; ` `    ``} ` ` `  `    ``if` `(b != c) { ` `        ``cout << ``"b is not equal to c\n"``; ` `    ``} ` `    ``else` `{ ` `        ``cout << ``"b is equal to c\n"``; ` `    ``} ` `    ``if` `(a == c) { ` `        ``cout << ``"a is equal to c\n"``; ` `    ``} ` `    ``else` `{ ` `        ``cout << ``"a is not equal to c\n"``; ` `    ``} ` ` `  `    ``return` `0; ` `} `

Output :

```a is not equal to b
b is not equal to c
a is equal to c
```

Rated as one of the most sought after skills in the industry, own the basics of coding with our C++ STL Course and master the very concepts by intense problem-solving.

My Personal Notes arrow_drop_up Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Improved By : shubham_singh

Article Tags :
Practice Tags :

Be the First to upvote.

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.