Java Full Basic For Learn

Java Programming Language

Posted by indranil on Jan. 5, 2021, 10:29 a.m.

Java Basic Programm For Learn---

 

package com.gositestore;

import java.util.Scanner;

public class Main {

static int sum(int a, int b){
return a+b;
}

public static void main(String[] args) {
// Write your code here
// System.out.println("Hello World");
/* Variables
Just Like:
-Water - Bucket
-Masala - box
-Lunch - LunchBox
In Java:
Variables are containers which store data values
String, int, float, char, boolean
How to declare variables:
syntax - <dataType> <variableName> = <value>;
*/
String name = "Harry";
String channel = "CodeWithHarry";
// System.out.println(name);
// System.out.println(name.length());
// System.out.println(name.toUpperCase());
// System.out.println(name.toLowerCase());
// System.out.println(name + " from\" " + channel);
// System.out.println(name + " from\\ " + channel);
// System.out.println(name + " from\t " + channel);
// System.out.println(name + " from\n " + channel);

// System.out.println(name.contains("Har"));
// System.out.println(name.charAt(2));
// System.out.println(name.endsWith("ry"));
// System.out.println(name.indexOf("rry"));

int numb1 = 4, numb2 = 7;
// System.out.println(Math.max(numb1, numb2));
// System.out.println(Math.min(numb1, numb2));
// System.out.println(Math.sqrt(36));
// System.out.println(Math.abs(-36));
// System.out.println(Math.abs(6));
// System.out.println(Math.random());
// System.out.println(4+(8-4)*Math.random());
// System.out.println(4+(8-4)*Math.random());
// System.out.println(4+(8-4)*Math.random());
// System.out.println(4+(8-4)*Math.random());
// System.out.println(4+(8-4)*Math.random());



int a = 45, x=56, y=67;
float b = 45.22f;
boolean isAdult = false;
// System.out.println(x);
// System.out.println(b);
// System.out.println(isAdult);

/* Rules for constructing name of variables in Java
1. Can contain digits, underscores, dollar signs, letters
2. Should begin with a letter, $ or _
3. Java is case sensitive language which means that
harry and Harry are two different variables altogether.
4. Should not contain whitespaces
5. You cannot use reserved keywords from Java
*/
/*
Two types of Java Data Types:
1. Primitive - byte (1 byte), short (2 bytes), int(4 bytes), long (8 bytes), float(4 bytes),
double (8 bytes), boolean(1 bit), char (2 bytes).
2. Non Primitive or Reference Data Type -
*/
byte u = -56;
double d = 45.635435345d;
// System.out.println(d);
char grade = 'A';
// System.out.println(grade);

/* Operators in Java

Operand, operator, Operand = Result
4 + 7 = 11

Types of operators in Java
Arithmetic operators
Assignment operators
Logical Operators
Comparison Operators
*/
int num1 = 45, num2=78;
num1 += 3;
num2 -= 8;
// Explore these operators - *=, /=, %=
// System.out.print("The value of num1 + num2 is ");
// System.out.println(num1 + num2);
//
// System.out.print("The value of num1 - num2 is ");
// System.out.println(num1 - num2);
//
// System.out.print("The value of num1 * num2 is ");
// System.out.println(num1 * num2);
//
// System.out.print("The value of num1 / num2 is ");
// System.out.println(num1 / num2);
//
// System.out.print("The value of num1 % num2 is ");
// System.out.println(num1 % num2);
// System.out.println(num2++);
// System.out.println(++num1);
// System.out.println(num1--);
// System.out.println(--num1);

/*
* Comparison Operators:
* 1. == : checks for equality of two values
* 2. != : checks if two values are not equal
* 3. <
* 4. >
* 5. <=
* 6. >=
*
* Logical Operators:
* 1. && - Logical and operator - returns true only if both conditions are true
* 2. || - Logical or operator - returns true if any one condition is true
* 3. ! - Logical not - Reverse the result from true to false and vice versa
* */

// Taking user input in Java
// Scanner scan = new Scanner(System.in);
// System.out.println("Enter Your Age");
// int age = scan.nextInt();
// System.out.println(input);

// If-else conditionals
// if(age>20){
//
// System.out.println("You are an adult");
// }
// else if(age>5){
// System.out.println("You are not a kid");
//
// }
// else{
// System.out.println("You are a kid");
// }
// Switch statement in Java

// switch (age){
// case 12:
// System.out.println("You are 12 years old");
// break;
// case 56:
// System.out.println("You are 56 years old");
// break;
// case 16:
// System.out.println("You are 16 years old");
// break;
// default:
// System.out.println("You did not match any of the cases");
// }
// Quick Quiz: print sunday to saturday based on numbers 1 to 7 typed by the user

// Loops
/*
While Loop
while(condition){
// This code will keep executing until the condition is true
}
*/
// int i = 0;
// while(i<100){
// System.out.println(i);
// i += 1;
// }

/*
Do While Loop
do{
// This code will keep executing until the condition is true
}while(condition)
*/
// int j = 0;
// do{
// System.out.println(j);
// j += 1;
// }while(j>100);

/*
For Loop
for(st1;st2;st3){
//Code to be executed
}
*/
//
// for(int i=0;i<=10;i++){
// if(i==2){
// continue;
// }
//// else{
//// System.out.println(i);
//// }
// System.out.println(i);
// }

// Java Arrays
// int [] marks = {1,2,3,5};
// marks[3] = 34; // this will update marks[3]
// System.out.println(marks[0]);
// System.out.println(marks[3]);
//
// // Classical way to iterate an array
// for(int i=0;i<marks.length;i++){
// System.out.println(marks[i]);
// }
// System.out.println("This is for each loop:");
//
// // For each loop
// for(int value:marks){
// System.out.println(value);
// }
//
// int [][] matrix = {{1,2,3},
// {4,5,6}};
// System.out.println(matrix[0][1]);
//
// String [] cars = {"Maruti Harry", "Maruti", "Suzuki", "Innova", "Ford Titanium"};
// for(String value:cars){
// System.out.println(value);
// }

// Try - Catch
// String [] cars = {"Maruti Harry", "Maruti", "Suzuki", "Innova", "Ford Titanium"};
//
// try{
// System.out.println(cars[3]);
// }
// catch(Exception e){
// System.out.println(e);
// }
//
// System.out.println("Masoom");
// System.out.println(sum(5, 7));

float number_1, number_2;
System.out.println("Enter first number");

Scanner scan = new Scanner(System.in);
number_1 = scan.nextFloat();

System.out.println("Enter second number");
// Scanner scan2 = new Scanner(System.in);
number_2 = scan.nextFloat();
System.out.print("You have Entered ");
System.out.print(number_1);
System.out.print(" and ");
System.out.println(number_2);
String prompt = "Enter 0 for addition, 1 for " +
"subtraction, 2 for multiplication and 3 for division";
System.out.println(prompt);
int input = scan.nextInt();
switch (input){
case 0:
System.out.println("Adding these numbers");
System.out.print("The result is: ");
System.out.println(number_1 + number_2);
break;

case 1:
System.out.println("Subtracting these numbers");
System.out.print("The result is: ");
System.out.println(number_1 - number_2);
break;

case 2:
System.out.println("Multiplying these numbers");
System.out.print("The result is: ");
System.out.println(number_1 * number_2);
break;

case 3:
System.out.println("Dividing these numbers");
System.out.print("The result is: ");
System.out.println(number_1 / number_2);
break;

default:
System.out.println("Invalid input");

}


}
}


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