Multiplying vector element by every other one

Question

Let's assume I have a vector

Vec[5] = {a1, a2, a3, a4, a5}

How can I make a method that multiplies:

a1*a2, a1*a3, a1*a4, a1*a5
a2*a3, a2*a4, a2*a5
a3*a4, a3*a5
a4*a5

Thanks!

Answer 1

Use a nested loop:

for (int i = 0; i < vec.length - 1; i++)
    for (int j = i + 1; j < vec.length; j++)
        // do something with i*j
        System.out.print(i*j + " ");