Skip to main content

java array

Array:-Array is special type of variable which can store multiple values into a single variable but all the values must be same. In java array is object.
How to use array:-
1.     Declaration of array
2.     Create array
Syntax for array declaration:-
type arrayname[];
Or
type []arrayname;
For example
int a[];  or
int[]a;
Create array:-
a=new int[5];  or
int a[]=new int[5];
or
int []a=new int[5];
Example1:ArraY.java
class ArraY
{
public static void main(String[]args)
{
int []a;
a=new int[5];
System.out.println("length of array is : "+a.length);
}
}
Output:-
C:\JAVATECH>javac ArraY.java
C:\JAVATECH>java ArraY
length of array is : 5
Example2:- ArraY.java
class ArraY
{
public static void main(String[]args)
{
int []a;
a=new int[5];
System.out.println("length of array is : "+a.length);
System.out.println("Array elements are : ");
for(int i=0;i<a.length;i++)
{
a[i]=i+2;
System.out.println(a[i]);
}
}
}
Output:-
C:\JAVATECH>javac ArraY.java
C:\JAVATECH>java ArraY
length of array is : 5
Array elements are :
2
3
4
5
6
Example3:-ArraY.java
class ArraY
{
public static void main(String[]args)
{
int []a={10,20,30,40,50,60,70,80};
System.out.println("length of array is : "+a.length);
System.out.println("Array elements are : ");
for(int i=0;i<a.length;i++)
{
System.out.print(a[i]);
}
}
}
Output:-
C:\JAVATECH>javac ArraY.java
C:\JAVATECH>java ArraY
length of array is : 8
Array elements are:
10 20 30 40 50 60 70 80
2-D array:-two D array is used for creating table or matrix.
How to use array:-
1.     Declaration of array
2.     Create array
Syntax for array declaration:-
type arrayname[][];
Or
type [][]arrayname;
For example
int a[][];  or
int[][]a;
Create array:-
a=new int[3][3];  or
int a[][]=new int[3][3];
or
int [][]a=new int[3][3];

 Example1:- Test2D.java

 class Test2D
{
public static void main(String[]args)
{
int a[][]={{10,20,30},{40,50,60}};
int i,j;
System.out.println("matrix is");
for(i=0;i<=1;i++)
{
for(j=0;j<=2;j++)
{
System.out.print(a[i][j]+"\t");
}
System.out.println();
}
}
}

 Output:-
C:\javatech>javac Test2D.java
C:\javatech>java Test2D
matrix is
10      20      30

40      50      60

Example2:- Test2D.java
class Test2D
{
public static void main(String[]args)
{
System.out.println("Demo of 2 D array");
System.out.println("2 D array Declared");
int a[][];
int[][]b=new int[3][5];
a=new int[2][4];
System.out.println("2 D array ceated");
System.out.println("length of a matrix : "+a.length);
System.out.println("length of b matrix : "+b.length);
System.out.println("length of a[0] object matrix : "+a[0].length);
System.out.println("length of b[0] object matrix : "+b[0].length);
}
}
Output:-
C:\JAVATECH>javac Test2D.java
C:\JAVATECH>java Test2D
Demo of 2 D array
2 D array Declared
2 D array ceated
length of a matrix : 2
length of b matrix : 3
length of a[0] object matrix : 4
length of b[0] object matrix : 5
Example3:- Test2D.java
class Test2D
{
public static void main(String[]args)
{
System.out.println("Demo of 2 D array");
int a[][];
a=new int[2][2];

for(int i=0;i<2;i++)
{
for(int j=0;j<2;j++)
{
a[i][j]=i+j;
System.out.print(a[i][j]+"\t");
}
System.out.println();
}
}
}
Output:-
C:\JAVATECH>javac Test2D.java
C:\JAVATECH>java Test2D
Demo of 2 D array
0       1

1       2
Labels:

Comments

Post a Comment

Popular posts from this blog

Inner classes

Inner Classes:- class inside class or interface called inner class or nested class. Advantage of inner classes is grouping multiple classes and interfaces into a single class. Another big advantage of inner class is that inner class can happily access all the data or variables of outer class directly. Types of Nested classes:- There are two types of nested classes static and non-static nested classes. (A)Non –static inner classes:- 1)     Member inner class 2)     Anonymous inner class 3)     Local inner class (B)Static nested class Example1:-Outer.java class Outer { class Inner { void disp() { System.out.println("Hello This is Inner class Method"); } } public static void main(String[]args) { Inner in=new Inner(); in.disp(); } } Output:- C:\JAVATECH>javac Outer.java Outer.java:12: error: non-static variable this cannot be referenced from a static context Inner in=new Inner(); ...
Post a Comment
Read more

Inheritance-4

Example10:- class Student { Student() { System.out.println("This is super class Zero argument constructor"); } Student(String s) { System.out.println("This is super class One argument constructor"); } } class Test extends Student { Test() { super(null); System.out.println("This is sub class Zero argument constructor"); } public static void main(String[]args) { Test t=new Test(); } } Output:- C:\JAVATECH>javac Test.java C:\JAVATECH>java Test This is super class One argument constructor This is sub class Zero argument constructor Example11:- class Student { Student() { System.out.println("This is super class Zero argument constructor"); } Student(String s) { System.out.println("This is super class One argument constructor"); } } class Test extends Student { Test() { super(); super(null); System.out.println("This is su...
Post a Comment
Read more

Small concept about OOPs

Some small concept about OOPs:- In many books and website write about OOPs concepts as hundred percent object oriented, pure object oriented and partial object oriented language. Hundred percent object oriented:- In the hundred percent object oriented movie hero is object, without object program is incomplete that means can not execute program without object. Without class and object programming or application development is not possible. Example of hundred percent object oriented language is  Smalltalk . Pure object oriented:- In the object oriented cinema obviously object is the hero. In pure object oriented language object having same importance but in this having some relax that is without creating object we can successfully execute our application. So in the object oriented programming without class we cannot create or run our application, class is must. Example of pure object oriented language is  Java . Partial object oriented:- In this type of la...
Post a Comment
Read more