Java for loop vs. while loop. Performance difference?

Question

Assume i have the following code, there are three for loop to do something. Would it run fast if i change the most outer for loop to while loop? thanks~~

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Answer 1

You can calculate it yourself.

int length = 200;
int test = 0;
int[] input = new int[10];

long startTime = new Date().getTime();

for(int i = 1; i <= length; i++) {
    for (int j = 0; j <=length - i; j++) {
        for (int k = 0; k < length - 1; k++) {
            test = test + input[j + k];
        }
    }
}

long endTime = new Date().getTime();
long difference = endTime - startTime;
System.out.println("For - Elapsed time in milliseconds: " + difference);


test = 0;
input = new int[10];

int i = 0, j = 0, k = 0;

startTime = new Date().getTime();

while(i < length) {
    while(j <= length - i ) {
        while(k < length - 1) {
            test = test + input[j + k];
            k++;
        }
        j++;
    }
    i++;
}

endTime = new Date().getTime();
difference = endTime - startTime;
System.out.println("While - Elapsed time in milliseconds: " + difference);