package class0_0_printlnTiming_start;

/**
 * This is a start at reproducing the results shown near the beginning of the quarter on
 * actual runtimes. It is FAR from complete.
 *
 * Early results: System.out.println() is expensive!
 */
public class Timing {

    public static final long ITERATIONS = 4_000_000L;

    public static void main(String[] args) {
//        timeIt(()->   {
//            int x = 1;
//            for(long i = 0; i < ITERATIONS; i++) {
//                System.out.println("Just a little thing.");
//                x *=2;
//            }
//            System.out.println(x);
//        });
        timeIt(()->   {
            int x = 1;
            System.out.println("x = " + x);
            System.out.println("x = " + x);
        });
        timeIt(()->   {
            int x = 1;
            for(long i = 0; i < ITERATIONS; i++) {
                x *=2;
            }
            System.out.println("x = " + x);
            System.out.println("x = " + x);
        });
        timeIt(()->   {
            int x = 1;
            int y = 4;
            for(long i = 0; i < ITERATIONS; i++) {
                x *=2;
                y *=2;
            }
            System.out.println("x = " + x);
            System.out.println("y = " + y);
        });
        timeIt(()->   {
            int x = 1;
            for(long i = 0; i < ITERATIONS; i++) {
                x *=2;
            }
            System.out.println("x = " + x);
            System.out.println("x = " + x);
        });
        timeIt(()->   {
            int x = 1;
            System.out.println("x = " + x);
            System.out.println("x = " + x);
        });
        timeIt(()-> {});
    }

    private static void timeIt(Runnable task) {
        long startTime = System.nanoTime();
        task.run();
        long endTime = System.nanoTime();
        long totalTime = endTime-startTime;
        System.out.println("Time taken: "+((totalTime)/1_000_000.) + "ms ");
    }

}