It is easy to just get 4 numbers. But it is difficult to get 4 numbers which are different from each other. This is the code to get 4 different numbers.
public static void main(String[] args){
int[] answer = new int[4];
for(int i = 0; i < answer.length; i++){
Loop: while(true){
answer[i] = (int)(Math.random() * 10); //Random numbers between 0 and 9
for(int j = 0; j < i; j++){
//If one is same as one of the previous numbers, the loop is repeated
if(answer[j] == answer[i]) continue Loop;
}
break;
}
}
}
