The method swaps two numbers without a temporary variable by utilizing arithmetic operations: it first adds both numbers and stores the result in the first variable, then subtracts the second variable from the first to derive the original value of the first variable, now stored in the second. Lastly, it subtracts the new value of the second from the first to restore the original value of the second into the first. This process utilizes the commutative properties of addition and subtraction .

The program initializes a variable 'max' with the first element of the array. It then iteratively compares each element of the array with 'max'. If a larger element is found, 'max' is updated. This single pass through the array ensures an O(n) time complexity, making it efficient for finding the maximum value .

The program reverses a given string by utilizing the StringBuilder class, which has a 'reverse' method. The method takes the input string, creates a StringBuilder object with it, reverses the sequence of characters, and converts it back to a string using the 'toString' method, which is then printed as the reversed string .