do-while ループが必要です:
do {
//code
} while (expression);
ソース：
http://docs.oracle.com/javase/tutorial/java/nutsandbolts/while.html
おそらく次のようなものが必要です。
int[] done = new int[100];
int randomquestion;
do{
randomquestion = (int)(Math.random() * 83 + 1);
if(done[randomquestion] != 1)
{
//ask random question
//if answer is correct, set done[randomquestion] = 1
//else just let do-while loop run
}
//check if all questions are answered
} while (!areAllQuestionsComplete(done));
メソッド areAllQuestionsComplete(int[]) は次のとおりです。
private boolean areAllQuestionsComplete(int[] list)
{
for(int i = 0; i<list.length; i++)
{
if(list[i] != 1)
{
return false;//found one false, then all false
}
}
return true;//if it makes it here, then you know its all done
}
あなたの最新のコードを見る：
for(int i = 0; i<done.length; i++)
{
done[i] = 0;//need default values else wise itll just be NULL!!!
}
do{
ran = (int)(Math.random() * 83 + 1);
//before entering the do-while loop, you must set default values in the entire done[] array
if(done[ran] != 1)
{
//ask random question
//if answer is correct, set done[ran] = 1
//else just let do-while loop run
if (ran == 1) { //1
question = "kala";
rightanswer = "fish";}
if (ran == 2) { //2
question = "peruna";
rightanswer = "potato";}
if (ran == 3) { //3
question = "salaatti";
rightanswer = "cabbage";}
if (ran == 4) { //4
question = "kalkkuna";
rightanswer = "turkey";}
if (ran == 5) { //5
question = "kia";
rightanswer = "tikku";}
//YOU MUST HAVE EVERY CONDITION COVERED
//say your random number makes the number 10
//you dont set question to anything at all (hence getting null!)
System.out.println(question);
System.out.print("Vastaus?: ");
answer = in.readLine();
//if (answer == rightanswer){
//must use .equals with Strings...not ==
if (answer.equals(rightanswer)){
right++;
done[ran] = 1;}
else{wrong++;}
}
//check if all questions are answered
} while (!areAllQuestionsComplete(done));//use the method I wrote!
編集：
配列にデフォルト値を入れる必要があります。配列を作成するときのデフォルト値は null です。
int[] done = new int[100];//create array but everything is null
for(int i = 0; i<done.length; i++)
{
done[i] = 0;//need default values else wise it'll just be NULL!!!
}
//must be done before the do-while loop starts
最後に、乱数ジェネレーターが正しい範囲の数値を選択していることを確認してください。サイズが 100 の配列がある場合、そのインデックスは 0 ～ 99 になります。これは、done[100] がないことを意味します。done[0] から done[99] までです。
done[] のサイズが 5 の場合、done[0] から done[4] の範囲になります。つまり、次のようにランダムに生成する必要があります。
randomquestion = (int)(Math.random() * 5 );