在Java中，我嵌套循環，但它給了我一個錯誤消息

Question

我試圖用EXACT相同的格式循環練習，它不會導致像這樣的錯誤消息。和內環路（含int i）以完美工作之前，我公司推出的外環（與詮釋j）的：

private static void mBTI(){ 
    Scanner console = new Scanner(System.in); 
    Random rand = new Random(); 

    //Practice loop 
    int wtf = console.nextInt(); 
    for (int k = 1; k <= wtf; k++){ 
     for (int m = 1; m <= 2; m++){ 
      System.out.println("derp"); 
     } 
    }   

    //Error loop 
    System.out.println("How many results do you want? (Type a numerical value.)"); 
    int amount = console.nextInt(); 
    String[] types = {"E","I","N","S","F","T","J","P"}; 
    int loop = 0; 
    for(int j = 1; j <= amount; j++){ 
     for(int i = 1; i <= 4; i++){ 
      int randType = rand.nextInt(2); 
      randType = loop+randType; 
      System.out.print(types[randType]); 
      loop = loop+2; 
     } 
     System.out.println(""); 
    } 
} 

Answer 1

你可能剛開的索引越界異常。請確保使用randType = randType％types.length（或其他方法將randType保留在邊界內）。