Detailed Explanation of Dynamic Initialization of Java Array
- 2021-11-24 01:20:51
- OfStack
Concept
1. Array dynamic initialization only gives array length, and the system defaults to initialization value.
2. Format
Data type [] Array name = new data type [Array length];
int[] arr = new int[3];
Instances
package com.itheima.array;
public class Demo2Array {
/*
Dynamic initialization of arrays :
At initialization time , You need to specify the length of the array manually , The system assigns an initial value to the array container .
Dynamic initialization format :
Data type [] Array name = new Data type [ Length of Array ];
Attention :
When printing array variables, , The memory address of the array will be printed out
[I@10f87f48 :
@ : Separator
[ : The current space is 1 Array type
I : The type of data stored in the current array container
10f87f48 : 106 Binary memory address
0 1 2 3 4 5 6 7 8 9 a b c d e f
*/
public static void main(String[] args) {
// Data type [] Array name = new Data type [ Length of Array ];
// Pass new Keyword creates the 1 A int Array container of type , This container can store 5 A int Integer of type , The container is arr Array variable
int[] arr = new int[5];
// [I@10f87f48
System.out.println(arr);
byte[] bArr = new byte[3];
// [B@b4c966a
System.out.println(bArr);
}
}
Extension of knowledge points:
1. What is the initialization of an array
Is to open up a continuous memory space for the array and assign a value to each array element
2. How to initialize an array
"1" Dynamic initialization only specifies the length, and the initialization value is given by the system
int[] arr = new int[5];
"2" Static initialization gives the initialization value, and the length is determined by the system
3. Dynamic initialization format:
Data type [] Array name = new data type [Array length];