Gain insights into Java essentials, including programming paradigms, objects, data types, and algorithms. Delve into extensive exercises to prepare for a software development career.

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java_common-new

This course is your detailed guide to the fundamentals of the Java programming language. This course will get you on the fast track to becoming a proficient and modern Java developer.

In this course, you will start by covering different programming paradigms like object-oriented and procedural programming. You will then cover the fundamentals of programming in Java such as: objects and data types, variables, arrays, and conditional statements.

In the latter half of the course, you will cover iterative constructs, useful algorithms, and data structures. With over 100 problems, 11 quizzes, and 9 challenges, this course will get you prepared for a career in software development.

A Complete Guide to Java Programming

According to the situation, it depends whether we should use `for` loop or `while` loop statement.

# `while` loop

## Example: 1


In many cases, the `while` loop is the best remedy. Suppose, we want to take integer inputs from the user and give the output of the average value. While writing the code, we will decide how many times the user will type the value. In the following code, the user is restricted to giving five values.


Once the user reaches the range, the average will come out automatically. If you want to rerun the code, write `java main` in the terminal: 

//code snippet to find the average of five numbers

import java.util.Scanner;

public class main {

    public static void main(String[] args) {

        final int listSize = 5;
        double valueOfSum = 0;
        int valueProcessed = 0;

        System.out.println("Please enter " + listSize + " numbers.");
        Scanner sc = new Scanner(System.in);
        while (valueProcessed < listSize){
            double yourNumber;
            yourNumber = sc.nextDouble();
            valueOfSum += yourNumber;
            valueProcessed++;
        }
        double averageOfYourNumbers = valueOfSum / valueProcessed;
        System.out.println("The average of given numbers " + averageOfYourNumbers);


    }
}

import React from 'react';
import { shallow, configure } from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

configure({ adapter: new Adapter() });

import HelloWorld from './app';

var TestResult = function() {
    this.succeeded = false;
    this.reason = "";
    this.input = "";
    this.expected_output = "";
    this.actual_output = "";
}

export const executeTests = function() {

  var results = [];

  result = new TestResult();
  result.input = 'HelloWorld Component';
  result.expected_output = "span containing text 'Hello World'"

  let wrapper = shallow(<HelloWorld />);

  // Call your Challenge function here.

  let type = wrapper.type();
  let testSuccessful = true;
  let failureReason;

  if (type !== 'span') {
    testSuccessful = false;
    failureReason = "You need to render exactly one span HTML element";
  } else if (wrapper.props().children != "Hello World") {
     testSuccessful = false;
     failureReason = "You have rendered wrong message in your span element";
  }

  result.actual_output = wrapper.html();

  if (testSuccessful) {
    result.succeeded = true;
    result.reason = "Succeeded"
  } else {
    result.succeeded = false;
    result.reason = failureReason;
  }

  results.push(result);

  return results;
}


React

Dart

GoJS React

Typescript React

Vue.js

### Code explanation

If we run the code, the user is prompted to give five values. After entering five values, the user will no longer be able to enter any more values. Our program will continue adding five values, and in the end, it will give the average.


The advantage of using the `while` loop is that it checks the condition precisely five times; after that, the loop terminates automatically and gives us the desired result.

## Example: 2

We could modify the above loop to make it more robust. The limitation of the above code is that the users are restricted to a certain number. Here we had restricted them to five. We could have made it 10 or 20 but, that doesn’t give them enough freedom. The users should be able to enter as many numbers as possible and get the average of the numbers. 

We could instruct the user how to terminate the program so that after a certain number, the user will stop. If you want to rerun the code, write `java main` in the terminal. The code is as follows:

Learn which loop(`for` or `while`) to choose according to given situations in this lesson.

Java, a High Level Language with a Purpose

How Java Programming Works

Objects and Data Types

Variables: The Name of a Field

Arrays: The Container Objects

Operators and Conditional Statements

Iterative Constructs, Entry and Exit Controlled Loops

Algorithms

Basic Input and Output

Classes and Objects

Interface and Abstraction

Exception Handling and Data Structures

Conclusion

Appendix

`for` or `while`, It Depends

`while` loop

Example: 1

`for` or `while`, It Depends

while loop

Example: 1

`while` loop