ARRAY

programs

args=new String[1];
System.out.println(args);
System.out.println(args.length);
args[0]=”hi”;
System.out.println(args[0]);

Prinnting total in array

int total=0;
Scanner sc=new Scanner(System.in);
int len=sc.nextInt();
int[] marks=new int[len];
for(int i=0;i<len;i++)
{
System.out.println(“please enter your marks”);
marks[i]=sc.nextInt();
total=total+marks[i];
}
System.out.println(total);
sc.close();

Printing array values & array reverse

    int[] array= {5,10,15,6,3};
    for(int i=0;i<array.length;i++)
    {
        System.out.println(array[i]);
    }
    for(int i=array.length-1;i>=0;i--)
    {
        System.out.println(array[i]);
    } 

Printing array index no

    int[] array= {5,10,15,6,3};
    for(int i=0;i<array.length;i++)
    {
        if(array[i]==15)
        System.out.println(i);
        break;
    }

Printing array value using index no

int[] array= {5,10,15,6,3};
for(int i=0;i<array.length;i++)
{
if(i==2)
System.out.println(array[i]);
break;
}

Linear search

boolean noPresent=false;
int[] marks= {91,76,92,89,98};
for(int i=0;i<marks.length;i++)
{
if(marks[i]==61)
{
System.out.println(“I got it”);
noPresent=true;
break;
}
}
if(noPresent==false)
{
System.out.println(“no is not present”);
}

Shifting all the elements towards left once

int []m= {91,76,92,89,98};
int i=0;
int temp=m[i];
while(i<m.length-1)
{
m[i]=m[i+1];
i++;
}
m[i]=temp;

Java predefined packages

• java.lang
• java.math
• java.util
• java.sql
• java.net
• java.io
• java.javax
• java.awt

Scope of variable

Whenever we declare a variable, the scope (life) of variable lies only in between its opening curly brace and its pair closing brace. (e.g) { }

Two dimentional Array

int [] [] marks= new int [3] [5];

Three dimentional Array

int [] [] []= new int [40] [3] [5];

Note: Java support ‘n’ dimentional array

sc.close( ); —–> memory leakage avoiding

Array Disadvantage

• Continuous memory
• Unused memory wasted

Swapping Array Values

int [] m={91,72,92,89,98};

m[2]=m[2]+m[4];

m[4]=m[2]-m[4];

m[2]=m[2]-m[4];

char [] name={‘c’,’b’,’a’};

name[0]=name[0]

Swapping towards left

int [] m={91,76,92,89,98};

int temp=m[0];

m[0]=m[1];

m[1]=m[2];

m[2]=m[3];

m[3]=m[4];

m[4]=temp;