Update FibonacciNumber.java (TheAlgorithms#4195)

Author: Indrranil

src/main/java/com/thealgorithms/maths/FibonacciNumber.java

@@ -17,27 +17,26 @@ public static void main(String[] args) {
      * Check if a number is perfect square number
      *
      * @param number the number to be checked
-     * @return <tt>true</tt> if {@code number} is perfect square, otherwise
-     * <tt>false</tt>
+     * @return <tt>true</tt> if {@code number} is a perfect square, otherwise
+     *         <tt>false</tt>
      */
     public static boolean isPerfectSquare(int number) {
         int sqrt = (int) Math.sqrt(number);
         return sqrt * sqrt == number;
     }
 
     /**
-     * Check if a number is fibonacci number This is true if and only if at
+     * Check if a number is a Fibonacci number. This is true if and only if at
      * least one of 5x^2+4 or 5x^2-4 is a perfect square
      *
      * @param number the number
-     * @return <tt>true</tt> if {@code number} is fibonacci number, otherwise
-     * <tt>false</tt>
+     * @return <tt>true</tt> if {@code number} is a Fibonacci number, otherwise
+     *         <tt>false</tt>
      * @link https://en.wikipedia.org/wiki/Fibonacci_number#Identification
      */
     public static boolean isFibonacciNumber(int number) {
-        return (
-            isPerfectSquare(5 * number * number + 4) ||
-            isPerfectSquare(5 * number * number - 4)
-        );
+        int value1 = 5 * number * number + 4;
+        int value2 = 5 * number * number - 4;
+        return isPerfectSquare(value1) || isPerfectSquare(value2);
     }
 }