Java. How to write random with an exception?

Question

Java

Tell me please. I need to assign a random array index to a variable, except for a specific one. How to implement it?

Answer 1

If I understand your problem correctly

int[] array = {1, 2, 3};

int badIndex = 1;
int variable;

int i;

Random random = new Random();

do {
    i = random.nextInt(array.length);
}while (i == badIndex);

variable = i;

Answer 2

You create an array of valid indices, throw a random from 0 to the size of this array, take this random element of the array - it will be the index.
Pseudocode like this:

int[] validIndexes = {0,1,2,5,6,7,9,10};
int random = random.nextInt(validIndexes.length);
int validIndex = randomIndexes[random];