Question

I’m trying to write an application which will populate an array with random numbers. Everything seems to work fine until I try to enter the for loop in my populateArray method.

import java.util.Random;

public class PerformanceTester {

//takes an empty array, but the size must be allocated BEFORE passing 
//to this function. Function takes a pre-allocated array and input size.
public static int[] populateArray(int[] inputArray, int n) {

    //Create the number generator
    Random generator = new Random();

    int length = inputArray.length;
    System.out.println("Inputted array is length: " + length);

    for (int i = 0; i == length; i++) {
        // for debugging purposes: System.out.println("For loop entered.");
        int random = generator.nextInt((2 * n) / 3);
        // for debugging purposes: System.out.println("Adding " + random + " to the array at index " + i);
        inputArray[i] = random;

    }
    return inputArray;
    }

public static void main(String[] args) {

    int[] input;
    input = new int[10];
    int[] outputArray = populateArray(input, 10);
    System.out.print(outputArray[0]);

}
}

As shown by my output, the compiler clearly enters the method (when called on line 29) but seems to stop all execution when the for loop is reached. I’m 100% sure that my loop has proper initialization and termination operators, because length is equal to ten.

I’m honestly stumped, but like most cases, I’m certain its a very simple answer. My output is below:

Inputted array is length: 10
0 //The array is not populated with numbers, so all indexes of the array return zero.

Any and all help is greatly appreciated.

Answer 1

Surely you meant your loop test to be this right?

for (int i = 0; i < length; i++) {

Otherwise, i == length will never be true (unless length == 0) and it will never enter the loop.

You also could have used:

for (int i = 0; i != length; i++) {