Forem: pranavinu

if-else - Task

pranavinu — Wed, 01 Apr 2026 13:52:29 +0000

1)

let csk=4;
let rcb=5;
let mi =5;
if(csk>rcb && csk>mi) 
{
    if(csk!=rcb && mi)
    {
        console.log("csk won");
    }
}

 else if(rcb>csk && rcb>mi)
{
    if(rcb!=mi && csk)
    {
        console.log("rcb won");
    }

}

    else if(mi>csk && mi>rcb)
    {
        if(mi!=csk && rcb)
    {
        console.log("mi won");
    }

    }
  else if(csk==rcb || csk==mi)
{
    console.log("tiebreaker");
}

 else if(mi==csk || mi==rcb)
{
    console.log("tiebreaker");
}
else if(rcb==csk || rcb==mi)
{
    console.log("tiebreaker");
}
else
{
    console.log("");
}

// tiebreaker

2)

let amount=4635;
let isMember=true;

if(amount>=5000 && isMember==true)
{
    console.log("final price with 30 percentage ="+amount*30/100);

}
else if(amount>=5000 && isMember==false)
{
    console.log("final price with 20 percentage ="+amount*20/100);

}
else if(amount>=2000 && isMember==true)
{
    console.log("final price with 20 percentage ="+amount*20/100);
}
else if(amount>=2000 && isMember==false)
{
    console.log("final price with 10 percentage = "+amount*10/100);
}
else{
    console.log("no discount"+amount);
}

//final price with 20 percentage =463.5

3)

let username="admin";
let password=1234;
if(username=="admin" && password==1234)
{
    console.log("user is not blocked");
}
else if(username=="admin" && password!=1234)
{
    console.log("Enter the valid password");
}
else if(username!="admin" && password==1234)
{
    console.log("Enter the valid user");
}
else
{
    console.log("enter the valid username and password");
}

// user is not blocked

4)

let signal_colour="yellow";
if(signal_colour=="red")
{
    console.log("stop");
}
else if(signal_colour=="yellow")
{
    console.log("Get ready");
}
else if(signal_colour=="green")
{
    console.log("go");
}
else
{
    console.log("");
}

// Get ready

5)

let balance=1000;
let withdrawlamount=50;
let debit=2500;
let userwithdrawlamount=true;

if(userwithdrawlamount==true && withdrawlamount<balance && withdrawlamount>=0)
{
    console.log("user withdrawlamount="+withdrawlamount);
    balance=balance-withdrawlamount;
    console.log("remaning balance="+balance);

}
else if(withdrawlamount>balance)
{
    console.log("insufficient balance")
}
else if(withdrawlamount<=0)
{
    console.log("invalid amount");
}
else 
{
    balance=balance+debit;
    console.log("amount debit="+balance);
}

//withdrawlamount=50
//remaning balance=950

6)

let data_usage= 72;

if(data_usage>=100)
{
    console.log("limit exceeded");
}
else if(data_usage>=80)
{
    console.log("warnimg:nearing limit");
}
else
{
    console.log("usage normal");
}

// usage normal

7)

let bill=247;
if(bill<=100)
{
    bill=bill*5;
    console.log("total bill ="+bill);
}
else if(bill<=300)
{
    bill=bill*7;
    console.log("total bill ="+bill);
}
else 
{
    bill=bill*10;
    console.log("total bill ="+bill);       
}

// total bill =1729

if-else,switch,and Ternary opreator in JS

pranavinu — Tue, 31 Mar 2026 12:53:03 +0000

if statement:

It is a conditional statement,that excute when the condition is true

if-else statement:

It is to check the multiple condition

else statement:

It excute when the condition is false

let mark =76;

if(mark>=90)
{
console.log("O")

}
else if(mark>=80)
{
console.log("A")

}
else if(mark>=70)
{
console.log("B")

}
else if(mark>=60)
{
console.log("C")

}
else if(mark>=50)
{
console.log("D")

}
else
{
console.log("No Grade")

}

switch:

It check the a variable value against multiple case value and excute the matching case

let op ='+';
let a=5;
let b=10;
switch(op)
{
case '+':
console.log(a+b);
break;
case '-':
console.log(a-b);
break;
case '*':
console.log(a*b);
break;
default :
console.log();
break;
}

Ternary operator:

It is an alternative of if-else statement
It is to check the simple if-else situation Syntax: variable = condition ? true value : false value;

let num=23;
let result = num%2==0 ? "even":"odd";
console.log(result);

Truthy

if a condition has a true value,it is treated as true

Truthy values:

non-zero numbers
non-empty strings
boolean(true)
arrays []
objects{}

Falsy

if a condition has a false value,it is treated as falsy

Falsy values:

boolean(false)
0
-0
empty
null
undefined +nan

Opreator in JS

pranavinu — Mon, 30 Mar 2026 12:53:07 +0000

Operator

1)It performs operation on variables and values

Arithmetic operator:

1)It performs an operation like(add,sub,..etc)

Add operator:

It is to add two values

let a=10;
let b=20;
console.log(a+b);

Concatenation:

Joining the strings a with another (string or values)

let e="5"
console.log("Enter the number "+e);

Subract:

It is to subract two values

let c=10;
let d=20;
console.log(c-d);

type casting:

Converts a value from one data type to another datatype,(string to number)

let i=10;
let s="20";
console.log(i-s);

Multiplication:

1)it is to multiple the two values

let c=10;
let d=20;
console.log(c*d);

Division:

It gives a quotient

let c=10;
let d=20;
console.log(c/d);

Modulus:

It gives a reminder

let c=10;
let d=20;
console.log(c%d);

Exponential:

It rises the left value to the power of the right value

let c=2;
let d=3;
console.log(c**d);

Assignment operator:

It is to assign the values to the variable

let d=20;
console.log(d);

Comparison operator:

1)It is to compare the two values
2)It returns a boolean values

Equality:

It is to check the values are same

let i=2;
let s=3;
console.log(i==s);

Strict equality operator:

It is to check the values are same and has a same datatype

let i=2;
let s="3";
console.log(i===s);

Inequality operator:

It is to check the values are not same

let i=2;
let s=3;
console.log(i!=s);

Strict inequality operator:

It is to check the values are not same or not of the same datatype

let i=2;
let s="3";
console.log(i!==s);

Less than operator:

It is to check if the left value is less than the right value

let i=2;
let s=3;
console.log(i<s);

Greater than operator:

It is to check if the left value is greater then the right value

let i=2;
let s=3;
console.log(i>s);

Less than or equal to operator:

It is to check if the left value is less than or equal to the right value

let i=2;
let s=3;
console.log(i<=s);

Greater than or equal to operator:

It is to check if the left value is greater then or equal to the right value

let i=2;
let s=3;
console.log(i>=s);

post-Increment:

It return the value first and then it gets incremented

let h=12;
console.log(h++);
console.log(h);

pre-Increment:

It increments the value first and then it returns the value

let h=12;
console.log(++h);

post-Decrement:

It return the value first and then it gets decremented

let h=12;
console.log(h--);
console.log(h);

pre-Decrement:

It decrement the value first and then it returns the value

let h=12;
console.log(--h);

let i=5;
let j=10;
let result =--i - --j - j-- + ++j;
console.log("result"+result);

output:-5

Exception handling tricky question

pranavinu — Mon, 16 Mar 2026 12:58:21 +0000

4)
{
int a[]= {10,20,30,40};
for(int i=0;i<=a.length;i++)
{
try {
int b=0;
System.out.println(a[i]/b);
}

        catch(ArithmeticException e)
        {
            System.out.println("invalid number");

        }
        catch(Exception E)
        {
            System.out.println(E.getMessage());
        }

    }
}

 }

2)
{
int a=10;

    try {
        int b=0;
        System.out.println(a/b);
    }
    catch(Exception e)
    {
        System.out.println("invalid number");
    }

}

 }

3)
{
int a=10;

    try {
        int b=5;
        System.out.println(a/b);
    }
    finally
    {
        System.out.println("invalid");
    }


}

 }

4)try {
int b=0;
System.out.println(a/b);
}
catch(Exception e)
{
System.out.println("invalid number");
}
finally
{
System.out.println(" Enter valid number");
}
5)It is already handled by the catch block for Exception

6)compilation problem
7)compilation problem
8)compilation problem
9)compilation problem
10)compilation problem
11)compilation problem
12)compilation problem
13)compilation problem
14){
int a[]= {10,20,30,40};

    for(int i=0;i<=a.length;i++)

    {
        try {
            int b=0;
            System.out.println(a[i]/b);
        }

        catch(RuntimeException e)
        {
            System.out.println("invalid number");


        }

        catch(Exception E)
        {
            System.out.println(E.getMessage());
        }

15)compilation problem

Exception handling scenerio based question

pranavinu — Mon, 16 Mar 2026 12:57:46 +0000

Division program:
1){

        int a = 10;

        int b = 0;
        int result=0;
        try {
            result = a / b;
        }
        catch(ArithmeticException e)
        {
            System.out.println("Enter valid number");


        }
        System.out.println("Result: " +

        result);




        } 

}

2)Array index program
{

        int arr[] = {10, 20, 30, 40};

        try
        {
            System.out.println(arr[5]);

        }
        catch(ArrayIndexOutOfBoundsException a)
        {
            System.out.println(a.getMessage());
        }



        }

}

String conversion program:
{
String s = "ABC";
int num=0;
try {
num = Integer.parseInt(s);
System.out.println(num);
}
catch(NumberFormatException n)
{
System.out.println(n.getMessage());

        }


        }

        }
NullpointerException:

{

    try {
        String name = null;

    System.out.println(name.length());

    }

    catch(NullPointerException n)
    {
        System.out.println(n.getMessage());
    }


    }

    }

File index program:
{

     {
         try {

         FileReader fr = new FileReader("test.txt");
         int data = fr.read();
         System.out.println(data);


         }
         catch(IOException e)
         {
             System.out.println(e.getMessage());
         }





         }


    }

    }

Class casting program:

{

public static void main(String[] args) {

Object obj = new Integer(10);

try {
String s = (String) obj;
System.out.println(s);
}
catch(ClassCastException e)
{
System.out.println(e.getMessage());
}

}
String index program:
{

public static void main(String[] args) {
    String str = "Java";

try {

    System.out.println(str.charAt(10));

}
catch(StringIndexOutOfBoundsException e)
{
System.out.println(e.getMessage());
}

}

negative array size:
{

    try {
    int size = -5;
    int arr[] = new int[size];
    }
    catch(NegativeArraySizeException E)
    {
        System.out.println(E.getMessage());
    }

    treeset program:

{

    TreeSet set = new TreeSet();

try {
set.add(10);

    set.add(30);

    set.add("hari");

    System.out.println(set);

}
catch(ClassCastException e)
{
System.out.println(e.getMessage());
}

}
}

treeset program
{

    TreeSet set = new TreeSet();
    try {
    set.add(20);

    set.add(40);

    set.add(null);
    }
    catch(NullPointerException e )
    {
        System.out.println(e.getMessage());
    }
    }
}



         }

File Handling

pranavinu — Mon, 16 Mar 2026 12:57:05 +0000

File Handling:
1)it is a pre-defined class and it is in an io package
2)it is process,to perform an opreation on file by set of codes
3)it consist of a CreateNewFile()-to create an empty file in a package or a particular location

{
File file=new File("C:\Users\tpavi\OneDrive\Music\sample2");
try {
file.createNewFile();
}
catch(Exception e)
{
System.out.println(" invalid");
}

}

FileWriter:
1)it is a pre-defined class and it is in io package
2)it is to write the statement inside the file by write()

{
try {
FileWriter file=new FileWriter("C:\Users\tpavi\OneDrive\Music\sample2");

    file.write("welcome java ");

    file.close();
}
catch(Exception e)
{
    System.out.println("");
}

}
}

FileReader():
1)it is a pre-defined class and it is in io package
2)it is to fetch the statement,which is inside the file by read()

{
file_reade fil=new file_reade();
fil.method1();

}

 void method1() {
    try {
    FileReader fr=new FileReader("C:\\Users\\tpavi\\OneDrive\\Music\\sample2");
    int c = 0;
    while(c!=-1)

    {

        System.out.print((char)c);
        c = fr.read();
    }
    fr.close();

}
    catch(Exception e)
    {
        System.out.println("inavaild");
    }

}

}

Map

pranavinu — Wed, 11 Mar 2026 09:45:15 +0000

Map:
1)It is an interface
2)It implement by the HashMap(pre-defined class)
Syntax:
HashMap<> map name=new HashMap();
3)It is to store the pair of keys and values
key-it allows to store unique values
values-it allows to store duplicate values
4)It allow the null values once
5)It consist of methods like (put(),remove(),containvalue(),containkey(),size(),get(),keyset(),values(),entryset())
put()-it is to store the values in a map
get()-it is to get the values in a map by keys
remove()-it is to remove the particular value by using key
containkey()-it is to check if map contains keys
containvalues()-it is to check if map contains value
size()-it is to find the size of the map
keyset()-it is to get only keys in a map,it should be unique
syntax:
setkeyset=map.keySet();
values()-it is to get only values in a map,it can have duplicate values
syntax:
collection collect =map.values();
entrySet()-it is to get both the keys and values,it should be unique
syntax:
Set>entry=map.entrySet();

String-task

pranavinu — Tue, 10 Mar 2026 14:29:05 +0000

10.Check Two Strings are Equal - Using equals method - Task
{

public static void main(String[] args) {

    String student1="rav i";
    String student2="mohan";

    System.out.println(student1.equals(student2));
    System.out.println(student1.replace(" ",""));

}

}

8)count the no of vowels in a String

{

public static void main(String[] args) {


    String name="ravi";
    int count=0;


    for(int i=0;i<name.length();i++)
    {
        char ch=name.charAt(i);
        switch(ch)
        {
        case'a':
        case'e':
        case'i':
        case'o':
        case'u':
             count=count+1;

            System.out.println(count);  
        }       
}

}
}

9).Count Words in a String - Using split method
{

public static void main(String[] args) {
    String student="ravi mohan ";
int a=student.split(" ").length;
System.out.println(a);

}
}

Jar files & Dpendancy

pranavinu — Thu, 05 Mar 2026 13:09:44 +0000

Maven project:
1)it is to built web application
2)it consist of many folders

Jar files(java Archive file)
1)Every tool has its own jar files
2)For a single tool it consist of many .class files
3)It is to access a pre defined class for a tool by importing jar files

Dependancy
1)Every tool has its own dependancy
2)It is in xml language
3)It is to access a pre defined class by attaching the dependency in pom.xml file
4)It can avoid version conflict by changing the version in depenency

Pom.xml:It is a file-to maintain dependency

Maven Repository-it is like a library,to maintain the dependency for a different tools

Java Collection

pranavinu — Wed, 04 Mar 2026 12:54:23 +0000

Framework:
1)It provides an pre defined class and libraries(java files) to devoleper to bulit an web application
2)It reduce devolepment time
3)The per defined class can be reused

JCF(java collection frame work):
1)It is a group of interface and class
interface-list,set,queue
class-ArrayList,HashSet,LinkedList

collection:
1)It is an interface
2)It can't create an object directly
3)It has three types
*list
*set
*queue

ArrayList:
1)It is a pre-defined class,and it is an util package
2)It implements the list(interface)
3)It can create the object directly
4)The ArrayList object consist of an pre defined methods like
(add(),contains(),isEmpty(),remove(index),remove(Strings),
set(index,element),get(index))
contain() and isEmpty()- will return boolean values
5)It allows store the values as an object
6)It allows to store the different datatypes in a object
7)It allows to store the multiple null values
8)It allows to store the duplicate values

HashSet:
1)It is a pre-defined class,and it is an util package
2)It implements the set (interface)
3)It don't follow the insertion order
4)It don't allow the duplicate values in array

treeset:
1)it is a pre defined class
2)it implements from linkedlist
3)it gives a sorted output
4)it don't allow the null value
5)it don't allow the duplicate value

LinkedList:
1)It is a pre-defined class,and it is an util package
2)It implements the list(interface)
3)It can create the object directly
4)The ArrayList object consist of an pre defined methods like
(add(),contains(),isEmpty(),remove(index),remove(Strings),
set(index,element),get(index))
contain() and isEmpty()- will return boolean values
5)It allows store the values as an object
6)It allows to store the different datatypes in a object
7)It allows to store the multiple null values
8)It allows to store the duplicate values
9)It works as node
node-works with values and address

Linked HashSet:
1)It is a pre-defined class,and it is an util package
2)It implements the set (interface)
3)It follow the insertion order
4)It don't allow the duplicate values in array

genreic:
1)it is to maintain the opreation in a similar datatype
2)it will show the exception at compiling
3)it is to avoid the casting exception
4)it is used for a pre-defined class like ArrayList,HashSet,TreeSet
Syntax:
HashSet list=new HashSet<>();

Array program

pranavinu — Wed, 04 Mar 2026 12:50:55 +0000

Array task :
1)Replace the value in an array

{

    int arr[]= {10,45,30,40};
    Scanner sc=new Scanner(System.in);
    System.out.println("enter user value");
    int user=sc.nextInt();

    Scanner sc1=new Scanner(System.in);
    System.out.println("enter a");
    int a=sc1.nextInt();


    for(int i=0;i<=arr.length-1;i++)
    {
        arr[a]=user;
        System.out.println(arr[i]);

    }
}

2)Find the smallest number in an array

{

public static void main(String[] args) {
    int a[]= {10,45,100,56,35,90};
    int minimum=a[0];
    for(int i=0;i<=a.length-1;i++)
    {
        if(minimum>a[i])
        {
            minimum=a[i];

        }
        System.out.println(minimum);
    }

}

}

Arrays

pranavinu — Fri, 27 Feb 2026 13:43:14 +0000

Arrays:
1)It is to store the multiple values in a single variable
Ex: int a[]={45,64,89};
2)Internally,it will create an object like,
int [] variable name=new int[size of the index];
int[]-array int
3)It can create an array object for primitives and non-primitives datatypes
4)In a variable,it allows to store only similar datatypes
5)For a variable,can't assign an values more then the size of the index
index-the index value starts form zero
Ex: int[] roll=new int[3];
roll[0]=10;
roll[1]=20;
roll[2]=30;