operator<= is the operator to determine if the left-hand instance is less or equal the right-hand instance.

The following code uses operator<= to determine that one plus two is less or equal equal to three:


#include <iostream>



int main()

{

  if (1 + 2 <= 3) std::cout << "One plus two is less or equal than three" << std::endl;

}

Advice

Reversing the order of the pair of symbols in the operators !=, >= and <= (by writing them as =!, => and =< respectively) is normally a syntax error [1]

References

Paul Deitel, Harvey Deitel. C++11 for programmers (2nd edition). 2014. ISBN: 978-0-13-343985-4. Chapter 2.4, Common Programming Error 2.2. page 32: 'Reversing the order of the pair of symbols in the operators !=, >= and < (by writing them as =!, => and =< respectively) is normally a syntax error. In some cases, writing != as =! will not be a syntax error, but almost certainly will be a logic error that has an effect at execution time.'