How to print the index of an array

Question

I have method where I run an array.

public static void findPairs(double[] c) {

    for (int i = 0; i < c.length; i++) {
        if (c[i] * c[i + 1] >= c[i] + c[i + 1]) {
            System.out.println();
            }   
    }
}

The array value:

c[0]0.5
c[1]1.5
c[2]2.0
c[3]2.0
c[4]3.0
c[5]5.02

I need to print the indexes of the array which are suitable in if expression. Is there some method and I don't know it?

For example:

(1,4) because 1.5*3.0 = 4.5 >= 4.5 = 1.5+3.0

(2,4) and (3,4) because 2.0*3.0 = 6.0 >= 5.0 2.0+3.0

etc.

Thanks

You'll run into an `ArrayIndexOutOfBoundsError` when your `i` reaches `c.length - 1` because `c[i+1]` is going to be out of bounds. — RealSkeptic, Jun 24 '15 at 14:19
I edited my answer to fit your format. Check it out. Happy programming! — marcelv3612, Jun 24 '15 at 14:30
I edited it once more, since I found another factual thing you have to change to make it work the way you want.BR — marcelv3612, Jun 24 '15 at 14:39
Possible duplicate of [How does System.out.print() work?](http://stackoverflow.com/questions/17121311/how-does-system-out-print-work) — andolsi zied, Nov 30 '16 at 13:19

marcelv3612 · Accepted Answer · 2015-06-24T14:38:46.110

Replace

System.out.println();

with

System.out.println('(' + c[i] + ',' + c[i+1] + ')');

Oh and one more thing, since you are not trying to pair a number with itself, you only want to reach second-to-last element, which you will try to pair with the last element. So also replace

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

with

for (int i = 0; i < c.length - 1; i++) {

But this still would not produce the result you want, i.e. (1,4) because you only try to pair n-th element with n+1-th element. You will need to use two loops, like this:

for (int i = 0; i < c.length - 1; i++) {
  for (int j = i; j < c.length; j++) {
    if (c[i] * c[j] >= c[i] + c[j]) {
       System.out.println('(' + c[i] + ',' + c[j] + ')');
    }
  }   
}

How to print the index of an array

1 Answers1