Array

 Q.        What is array?

A.        Array គឺជាបណ្តុំ Variables ដែលមានឈ្មោះដូចគ្នា និង Datatype ដូចគ្នា ហើយពួកវាខុស គ្នាដោយ Index ។ 

1.      One dimensional array

One dimensional array គឺសំដៅលើ Array មួយវិមាត្រ។

          Datatype         arrayName[ ] = new                Datatype[elements];

ឧទាហរណ៍៖

         

a[0]

a[1]

a[2]

a[3]

a[4]

ដើម្បីបញ្ជាក់ថា a ជា array លុះត្រាតែ a មានឃ្នាប​ [ ] ។

ចំណាំ៖

          ក្នុងភាសា Java យើងអាចបង្កើត array n ធាតុបាន ដោយសារតែចំនួន elements របស់វា យើងអាចប្រើ Variable ជំនួសបាន។

ឧទាហរណ៍៖

          int n;

n=cin.nextInt();

int a[]=new int[n];

      import java.util.Scanner;

public class InputArrayN{

public static void main(String arg[]){

Scanner cin=new Scanner(System.in);

int n;

System.out.print(“Enter n = ”);

n=cin.nextInt();

int a[]=new int[n];

System.out.println(“Now, you can enter ”+n+“ values”);

for(int i=0; i<n; i++){

System.out.print(“Enter a[“+i+”] = ”);

a[i] = cin.nextInt();

}

System.out.println(“Now, you can display ”+n+“ values”);

for(int i=0; i<n; i++)

            System.out.println(“a[“+i+”] = ”+a[i]);

}

}

      import java.util.Scanner;

public class Max{

public static void main(String []arg){

Scanner cin=new Scanner(System.in);

int n;

System.out.print(“Enter number of elements = ”);

n=cin.nextInt();

int a[]=new int[n];

System.out.println(“Now, you can enter ”+n+“ values”);

for(int i=0; i<n; i++){

System.out.println(“Enter a[“+i+”] = ”);

a[i]=cin.nextInt();

}

int max;

max=a[0];

for(int i=1; i<n; i++)

if(max<a[i])

            max=a[i];

System.out.println(“Maximum is ”+max);

}

}

សំគាល់៖

ក្នុងភាសា Java ត្រូវប្រកាស (Declare) ប្រភេទទិន្នន័យ (Datatype) ឡើងវិញ ព្រោះ វាត្រូវ Run នៅក្នុង for នេះសំរាប់ execute នៅក្នុង for ។

      import java.util.Scanner;

public class Main{

public static void main(String arg[]){

Scanner cin=new Scanner(System.in);

int n;

System.out.print(“Enter number of elements = ”);

N=cin.nextInt();

int a[]=new int[n];

System.out.println(“Now, you can enter ”+n+ “ values”);

for(int i=0; i<n; i++){

System.out.print(“Enter a[“+i+”] = ”);

a[i]=cin.nextInt();

}

for(int i=0; i<n-1; i++)

for(int j=1+i; j<n; j++)

if(a[i]>a[j]){

int temp;

temp=a[i];

a[i]=a[j];

a[j]=temp;

}

for(int i=0; i<n; i++)

System.out.println(“[“+i+”] = ”+a[i]);

}

}

      import java.util.Scanner;

public class Main{

public static void main(String arg[]){

Scanner cin=new Scanner(System.in);

int n;

System.out.print(“Enter number of elements = ”);

n=cin.nextInt();

int a[]=new int[n];

System.out.println(“Now, you can enter ”+n+ “values”);

for(int i=0; i<n; i++){

System.out.println(“Enter a[“+i+”] = ”);

a[i]=cin.nextInt();

}

int Search;

System.out.print(“Enter number you need to Search = ”);

Search=cin.nextInt();

System.out.print(“Index”);

boolean b=false;

for(int i=0; i<n; i++)

if(a[i]==Search){

b=true;

System.out.print(+i“,”);

}

if(b==true)

System.out.print(“Found in array.”);

else

System.out.print(“Not found in array.”);

}

}

      import java.util.Scanner;

public class Main{

public static void main(String arg[]){

Scanner cin=new Scanner(System.in);

int n;

System.out.print(“Enter number of elements = ”);

                                    n=cin.nextInt();

int a[]=new int[n];

System.out.println(“Now, you can enter ”+n+ “ values.”);

for(int i=0; i<n; i++){

if(i==0){

System.out.println(“Enter a[“+i+”] = ”);

a[i]=cin.nextInt();

}else{

System.out.println(“Enter a[“+i+”] = ”);

boolean b=false;

int value;

value=cin.nextInt();

for(int j=0; j<i; j++)

if(a[j]==value){

System.out.println(“Number already exist.”);

b=true;

break;

}

if(b==false)

a[i]=value;

}

}

System.out.println(“Now, you can display ”+n+ “ values”);

for(int i=0; i<n; i++)

            System.out.println(“a[“+i+”+a[i]] ”);

}

}

      d

2.      Multidimensional Array

សំដៅលើ Array ច្រើនវិមាត្រ។ ជាទូទៅ  គេច្រើនប្រើត្រឹមតែ ២វិមាត្រ។

FORM:

            DataType        ArrayName[][]=new               DataType[element1][element2];

ឧទាហរណ៍៖

                                       [2]=Row    [3]=Column                           

           int a[][]=new   int[2][3];

a[0][0]	a[0][1]	a[0][2]
a[1][0]	a[1][1]	a[1][2]

import java.util.Scanner;

public class InputArray2{

            public static void main(String arg[]){

                        Scanner cin=new Scanner(System.in);

                        int r, c;

System.out.print(“Enter rows = ”);

r=cin.nextInt();

System.out.print(“Enter columns = ”);

c=cin.nextInt();

int a[][]=new int[r][c];

for(int i=0; i<r; i++){

for(int j=0; j<c; j++){

System.out.println(“Enter a[“+i+”][“+j+”] = ”);

a[i][j]=cin.nextInt();

}

System.out.println();

}

System.out.println(“Now, you can display “+r+” Rows “+c+” Columns”);

for(int i=0; i<r; i++){

for(int j=0; j<c; j++)

            System.out.println(a[i][j] + “\t”);

}

System.out.println();

            }

}

import java.util.Scanner;

public class AddElementArray{

            public static void main(String arg[]){

Scanner cin=new Scanner(System.in);

int n;

System.out.print(“Enter n = ”);

                        n=cin.nextInt();

int a[]=new int[n];

for(int i=0; i<n; i++){

System.out.println(“Enter a[“+i+”] = ”);

a[i]=cin.nextInt();

}

int temp[];

temp=a;

int m;

System.out.print(“Enter m = ”);

m=cin.nextInt();

a=new int[n+m];

for(int i=0; i<n; i++)

a[i]=temp[i];

System.out.println(“Please, enter data for new elements.”);

for(int i=0; i<n+m; i++){

System.out.print(“Enter a[“+i+”] = ”);

a[i]=cin.nextInt();

}

for(int i=0; i<n+m; i++)

            System.out.println(“a[“+i+”] = ”+a[i]);

}

}

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