Java Array Chapter

Array is a variable that stores a set of data of the same data type (that is, a data type that can store many numeric values)

If declaring a variable is an appropriate space in the memory space, declaring an array is a contiguous set of spaces in the memory space.

Basic Requirements for arrays

• Identifier: The name of the array used to distinguish between different arrays
• Array elements: Data stored in an array
• Element subscript: Starting from 0
• Element type: The data type of the array

Basic steps for array manipulation

　　1) Declaring an array: Tell the computer what the data type is

data type [] array name; such as: int[] score1;

Data type array name []; such as: int score2[];

　Note: The length of an array cannot be declared when declaring an array

　　2) Allocate space: Tell the computer to allocate several contiguous spaces

such as: Score=new int[30];

    Data type []  new  data type [size];

　3) Assign Value

　　Edge Declaration Variable assignment value

Int [] score=new int[]{89,79,69}; There are 3 values in front of 3, the computer does not allow

Int[] score={89,69,79}

You can also use console input to assign values

Scanner  input =new  Scanner (system.in); for (int  i=0; i<30; i++) {score[i]=input.nextint ();}

Example:

/** Define an array sequence * The value of the loop output sequence number of all values in the series and * guessing games: Enter any data from the keyboard to determine if the number is included in the sequence*/ Public classTest01 { Public Static voidMain (String args[]) {int[] arr; Arr=New int[]{8,4,2,1,23,34,12}; intSum=0;  for(inti=0;i<arr.length;i++) {System.out.println (arr[i]); Sum=sum+Arr[i]; } System.out.println ("The sum of the array sequence is:" +sum); Scanner input=NewScanner (system.in); System.out.println ("Please enter a number:"); intj=Input.nextint (); intK=0;  for(inti=0;i<arr.length;i++){            if(j==Arr[i]) {k=1;  Break; }        }        if(k==1) {System.out.println (Contains); }Else{System.out.println ("Does not contain"); }    }}

Java Array Chapter