Java speed access array index versus temp variable

Question

What is faster in Java. Accessing an array index directly multiple times, or saving the value of the array index to a new variable and use this for following compution?

Answer 1

Array access could be faster. Note the following program:

public class ArraySpeedTest{

public static void main(String [] args){

    float x = 4.4f;
    float [] xArr = new float[1];
    xArr[0] = 4.4f;

    long time1 = System.nanoTime();
    for(int i = 0 ; i < 1000*1000*1000; i++){
        if(x > 1 && x < 5){

        }
    }
    long time2 = System.nanoTime();

    System.out.println(time2-time1);

    long time3 = System.nanoTime();
    for(int i = 0 ; i < 1000*1000*1000; i++){
        if(xArr[0] > 1 && xArr[0] < 5){
        }
    }
    long time4 = System.nanoTime();

    System.out.println(time4-time3);


}

}

OUTPUT:: 5290289 2130667

JVM implementations, flags, and order of the program can change the performance on the order of a few milliseconds.