java.lang.ArrayIndexOutOfBoundsException :10 even though the array can go up to 10

Question

即使我从中获取数据的文件的索引足以为 10，我在“if”语句中收到“java.lang.ArrayIndexOutOfBoundsException:10”错误。

当我在代码中的其他地方调用 info[10] 时，它可以工作，但我不知道为什么它在这里不起作用。

现在正在学习计算机科学中的文件管理单元...

public static void comSci(String onTheMap) throws IOException  
{         
    BufferedReader input = new BufferedReader (new FileReader ("data.txt"));
    if (onTheMap.equals("3")){    
        Scanner scanner = new Scanner("data.txt");
        String line="x";
        System.out.println("--------------------------------------------------------------");
        System.out.println("Create a file of student's who are enrolled in ICS3U0:");
        System.out.println("--------------------------------------------------------------");
        String info[] = new String[20];
        boolean finder = false;      

        while (line!=null) {
            line = input.readLine();
            if (line==null)
                break;        
            info = line.split(",");

            if (info[10].toLowerCase().contains("ICS3U0".toLowerCase())) {  //PROBLEM
                finder = true;
                String programmers = info[0] + "," + info[1];
                System.out.println(programmers);
                try {
                    FileWriter theFile = new FileWriter("ICS3U0.txt",true);
                    PrintWriter names = new PrintWriter(theFile);
                    names.println();
                    names.close();

                }
                catch (FileNotFoundException e) {
                    e.printStackTrace();
                }
            }  
        } 
        System.out.println("ICS3U0.TXT WAS CREATED");

    }
    input.close();

}

Answer 1

Java 数组索引从 0 开始。因此长度为 10 的数组具有 0-9(含 0-9)(或不含 0-10)的有效索引。这就是为什么 for 循环通常被设置样式，

for (int i = 0; i < arr.length; i++) { // <-- less than (not less than =).
   // ...
}