Java Syntax Basics-arrays

1. Concept

a collection of the same type of data.  The array is actually a container .

2. Benefits of Arrays

The elements in the array can be automatically numbered starting with 0, allowing them to be manipulated.

3. format 1:

element type [] array name = new element type [ element number or array length ];

int[] arr = new int[5];

4. format 2:

element type [] array name = new element type []{ element, element, ... };

I nt[] arr = new int[]{3,5,1,7};

int[] arr = {3,5,1,7};

Element type [] array name = new element type [ element number or array length ];

int x = 4;//a data.        NEW: The keyword used to create the entity int[] arr = new INT[3]; A variable that defines an array of type int elements arr,//creates an array entity with the New keyword that can store 3 elements of type int.

Allocation of arrays in memory

Please see attachment

FAQ for Arrays

Array Operations FAQ.    1.//arrayindexoutofboundsexception: Array angle label out of bounds exception, occurs at runtime int[] arr = new INT[3];    System.out.println (Arr[3]);. This exception occurs when a corner label that does not exist is accessed.    2.//nullpointerexception null pointer exception.    arr = null;    System.out.println (arr[1]); This exception occurs when the reference (ARR) does not have any entities pointing, and its action entity is also being used.

For example, the common operation of an array - the maximum value

Public static int getmax (Int[] arr) {&NBSP;&NBSP;&NBSP;&NBSP;//1, defines a variable and records a larger value.     int max = arr[0];//initialization is an array of any element     //2, traversing an array.     for  (int x=1; x<arr.length ;x++ )     { &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;//3, make a judgment comparison.         if (Arr[x]>max)              max = arr[x];     }       return max;  }  //the second maximum value. PUBLIC&NBSP;STATIC&NBSP;INT&NBSP;GETMAX2 (Int[] arr) {    int maxindex = The  0;   //is initialized to any of the corner labels in the array.     for  (int x=0; x<arr.length ;x++ )     {         if (Arr[x]>arr[maxindex]) {&NBSP;&NBSP;&NBSP;&Nbsp;     maxindex = x;        }} 

Java Syntax Basics-arrays