please teach me

小小爬爬

Below I wrote a small program that displays the first 20 numbers of the Fibonacci series.

It can be displayed at runtime, but it shows an exception in the end. What's the problem? as follows:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 20


public class Fibo {
public static void main (String [] args) {
int array [] = new int [20];
array [0] = 1;
array [1] = 1;
System.out.print (array [0] + "");
System.out.print (array [1] + "");
for (int i = 2; i <21; i ++) {
array [i] = array [(i-2)] + array [(i-1)];
System.out.print (array [i] + "");
}
System.out.println ();
}
}

chen96542

Array subscript is out of bounds.
int array [] = new int [20]; // This sentence creates an array of 20 ints with subscripts from 0-19;
for (int i = 2; i <21; i ++) {// When the execution reaches i = 20, the conditions are still met, and an exception will be reported when the array [i] is referenced

You can change to int array [] = new int [21];

Or for (int i = 0; i <20; i ++)

madcat1

java.lang.ArrayIndexOutOfBoundsException
Array subscript out of bounds Exception
Learn to look at Exception, it does n’t matter if you do n’t understand, translate it literally, and you can probably guess it

小小爬爬

ok, got it, thank you