Two common mistakes in the Java Learning array

Connecting the stack of the previous Java exploration, and the inner exploration of erasing, you can learn two ways to master array errors.

 Packagecom.dreamly.day01;/** * @authordreamly **/ Public classArrayTest01 { Public Static voidMain (string[] args) {int[] x=New int[3]; X=NULL;//erases the connection to the instance object, that is, the address value is not saved. System.out.println (x[0]); //nullpointerexception: null pointer exception, when reference does not have any point to a value of NULL, the reference is also used to manipulate the entity        /*** Exception in thread ' main ' java.lang.NullPointerException at Com.dreamly.day01.ArrayTest01.main (arraytes T01.JAVA:11)*/                int[] arr=New int[3]; System.out.println (arr[3]); //arrayindexoutofboundsexception: When manipulating an array, it accesses a corner label that does not exist in the array 00000        /** Exception in thread ' main ' Java.lang.arrayindexoutofboundsexception:3 at com.dreamly.day01.ArrayTest01 . Main (arraytest01.java:19)*/    }}

Two common mistakes in the Java Learning array