Java, The BasicsStart coding using Java

Marius Claassen

Java, The Basics

Start your programming journey, by

learning the essentials of the world’s

most popular language to discover:

• Java can be learnt

• Programming can be rewarding

• You can make a living from this skill

2Marius Claassen

Java, The Basics

About me

Marius Claassen, Java Developer and Teacher

I am a self-taught java developer. Having been a teacher for many

years, I am now working full-time as an independent software

instructor, making video tutorials. It is my mission to help others learn

programming in general and Java in particular.

3Marius Claassen

Java, The Basics

Benefits

• Read and write Java code

• Develop simple Java applications

• Devise basic Java solutions

4Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion5

Marius Claassen

Java, The Basics

Lecture outline

• 15 Lectures

• 5 minutes

1. Video

2. PDF

3. Coding exercise

6Marius Claassen

Java, The Basics

Lecture details

• Lesson topic

• Problem statement

• Coding exercise

7Marius Claassen

Java, The Basics

To access this course:

• https://www.udemy.com/course/1435298/manage/basics/

and

• http://skl.sh/2hGOtbV

or

• mariusclaassen@gmail.com

8Marius Claassen

Java, The Basics

Ideal student

Complete new-comer to Java

A gentle introduction by:• studying Java code

• doing coding exercises

• checking answers against solutions

9Marius Claassen

Java, The Basics

Enrolment

• 30-day money back guarantee

10Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion11

Marius Claassen

Java, The Basics

Lecture 2: Java overview

• General-purpose programming language

•

• First public release in 199512

James Gosling

Marius Claassen

Java, The Basics

Four characteristics:

• OpenThere are 12 million Java developers world-wide

• EvolvingAddition of functional programming techniques

• NimbleThere will be a new Java release every 6 months

• Scalable“When companies grow up they turn into Java shops”

13Marius Claassen

Java, The Basics

Java development process

object 13

14

HelloWorld.java Hello, worldHelloWorld.class

Compiler Java Virtual Machine (JVM)

Marius Claassen

Java, The Basics

Java’s popularity

object 13

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Java, The Basics

Java earnings

object 13

19Marius Claassen

Java, The Basics

object 13

20

indeed.comindeed.com

Lecture 2: Questions

1. Java is a

…………………………………………….

2. Java’s first public release was in

……

3. Java source files are changed into

dot …….. files by the

………………………………………….... 21

Marius Claassen

Java, The Basics

Lecture 2: Answers

1. Java is a general-

purpose programming language

2. Java’s first public release was in

1995

3. Java source files are changed into

dot class files by the

Java Virtual Machine (JVM) 22

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion23

Marius Claassen

Java, The Basics

Lecture 3: Hello world example

‘Hello world’ problem statement:

Implement ‘Hello world’ in Java.

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Java, The Basics

25

public class Lecture3 {

public static void main(String[] args) {

// Hello world

System.out.print(“Hello world”);

}

}

Marius Claassen

Java, The Basics

Lecture 3: First coding exercise

Write a statement to print the text, ‘Hi there’

in Java.

26Marius Claassen

Java, The Basics

Lecture 3: First coding exercise

27

public class Lecture4 {

public static void main(String[] args) {

// TODO: Print the text, ‘Hi, there’

}

}

Marius Claassen

Java, The Basics

Lecture 3: First coding exercise

28

public class Lecture4 {

public static void main(String[] args) {

}

}

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion29

Marius Claassen

Java, The Basics

Lecture 3: First coding exercise

Write a statement to print the text, ‘Hi there’

in Java.

30Marius Claassen

Java, The Basics

31

System.out.print(“Hi there”);

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Java, The Basics

32

public class Lecture4 {

public static void main(String[] args) {

// TODO: Print the text, ‘Hi, there’

}

}

Marius Claassen

Java, The Basics

33

public class Lecture4 {

public static void main(String[] args) {

}

}

Marius Claassen

Java, The Basics

34

public class Lecture4 {

public static void main(String[] args) {

System.out.print(“Hi there”);

}

}

// Hi there

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion35

Marius Claassen

Java, The Basics

Lecture 5: Primitive types example

‘Primitive’ data type problem statement:

Implement a ‘double’ data type,

‘doubleNumber’, initialized as 9781.3

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Java, The Basics

37

double doubleNumber = 9781.3;

Marius Claassen

Java, The Basics

Lecture 5: Primitive types example

38

public class Lecture5 {

public static void main(String[] args) {

}

// TODO: Implement ‘doubleNumber’ 9781.3

}

System.out.print(doubleNumber);

Marius Claassen

Java, The Basics

Lecture 5: Primitive types example

39

public class Lecture5 {

public static void main(String[] args) {

}

}

System.out.print(doubleNumber);

Marius Claassen

Java, The Basics

Lecture 5: Primitive types example

40

public class Lecture5 {

public static void main(String[] args) {

}

double doubleNumber = 9781.3;

}

System.out.print(doubleNumber);

// 9781.3

Marius Claassen

Java, The Basics

Lecture 5: Primitive type exercise

Implement an ‘int’ data type, ‘intValue’,

initialized as 4326.

41Marius Claassen

Java, The Basics

Lecture 5: Primitive type exercise

42

public class Lecture5 {

public static void main(String[] args) {

}

// TODO: Implement ‘intNumber’ as 4326

}

System.out.print(intNumber);

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion43

Marius Claassen

Java, The Basics

Lecture 5: Primitive type exercise

Implement an ‘int’ data type, ‘intValue’,

initialized as 4326.

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Java, The Basics

45

int intValue = 4326;

Marius Claassen

Java, The Basics

Lecture 5: Primitive type exercise

46

public class Lecture6 {

public static void main(String[] args) {

}

// TODO: Implement ‘intValue’ as 4326

}

System.out.print(intValue);

Marius Claassen

Java, The Basics

Lecture 6: Primitive type solution

47

public class Lecture6 {

public static void main(String[] args) {

}

}

System.out.print(intValue);

Marius Claassen

Java, The Basics

48

public class Lecture6 {

public static void main(String[] args) {

}

int intValue = 4326;

}

System.out.print(intValue);

// 4326

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion49

Marius Claassen

Java, The Basics

Lecture 7: Reference type example

‘Reference’ data type problem statement:

Implement a ‘String’ data type, ‘myBusiness’,

initialized as ‘AlefTav Coding’

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Java, The Basics

51

String myBusiness = “AlefTav Coding”;

Marius Claassen

Java, The Basics

Lecture 7: Reference type example

52

public class Lecture7 {

public static void main(String[] args) {

}

// TODO: Implement a String data type

}

System.out.print(myBusiness);

Marius Claassen

Java, The Basics

53

public class Lecture7 {

public static void main(String[] args) {

}

}

System.out.print(myBusiness);

Marius Claassen

Java, The Basics

54

public class Lecture7 {

public static void main(String[] args) {

}

String myBusiness = “AlefTav Coding”;

}

System.out.print(myBusiness);

// AlefTav Coding

Marius Claassen

Java, The Basics

Lecture 7: Reference type exercise

Implement a ‘String’ data type, ‘someText’,

initialized as ‘I am a student’

55Marius Claassen

Java, The Basics

Lecture 7: Reference type exercise

56

public class Lecture8 {

public static void main(String[] args) {

}

// TODO: Implement a String data type

}

System.out.print(someText);

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion57

Marius Claassen

Java, The Basics

Lecture 7: Reference type exercise

Implement a ‘String’ data type, ‘someText’,

initialized as ‘I am a student’.

58Marius Claassen

Java, The Basics

59

String someText = “I am a student”;

Marius Claassen

Java, The Basics

Lecture 7: Reference type exercise

60

public class Lecture8 {

public static void main(String[] args) {

}

// TODO: Implement a String data type

}

System.out.print(someText);

Marius Claassen

Java, The Basics

Lecture 8: Reference type solution

61

public class Lecture8 {

public static void main(String[] args) {

}

}

System.out.print(someText);

Marius Claassen

Java, The Basics

62

public class Lecture8 {

public static void main(String[] args) {

}

String someText = “I am a student”;

}

System.out.print(someText);

// I am a student

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion63

Marius Claassen

Java, The Basics

Lecture 9: Scanner class example

‘Scanner’ class problem statement:

Implement a ‘Scanner’ class data type,

‘input’, so that Java asks for your profession.

64Marius Claassen

Java, The Basics

import java.util.Scanner;

65

String job = input.nextLine();

Scanner input = new Scanner(System.in);

Marius Claassen

Java, The Basics

Lecture 9: Scanner class example

66

public class Lecture9 {

public static void main(String[] args) {

System.out.print(“Your profession: ” + job);

System.out.print(“What is your profession? ”);

// TODO: Implement String, as ‘job’

// TODO: Implement Scanner, as ‘input’

}

}

Marius Claassen

Java, The Basics

67

public class Lecture9 {

public static void main(String[] args) {

System.out.print(“Your profession: ” + job);

System.out.print(“What is your profession? ”);

}

}

Marius Claassen

Java, The Basics

import java.util.Scanner;

68

public class Lecture9 {

public static void main(String[] args) {

System.out.print(“Your profession: ” + job);

System.out.print(“What is your profession? ”);

String job = input.nextLine();

Scanner input = new Scanner(System.in);

}

}

Marius Claassen

Java, The Basics

import java.util.Scanner;

69

public class Lecture9 {

public static void main(String[] args) {

System.out.print(“Your profession: ” + job);

System.out.print(“What is your profession? ”);

String job = input.nextLine();

Scanner input = new Scanner(System.in);

}

} // What is your profession?

Marius Claassen

Java, The Basics

import java.util.Scanner;

70

public class Lecture9 {

public static void main(String[] args) {

System.out.print(“Your profession: ” + job);

System.out.print(“What is your profession? ”);

String job = input.nextLine();

Scanner input = new Scanner(System.in);

}

} // What is your profession? Java teacher

Marius Claassen

Java, The Basics

import java.util.Scanner;

71

public class Lecture9 {

public static void main(String[] args) {

System.out.print(“Your profession: ” + job);

System.out.print(“What is your profession? ”);

String job = input.nextLine();

Scanner input = new Scanner(System.in);

}

} // What is your profession? Java teacher

// Your profession: Java teacherMarius Claassen

Java, The Basics

Lecture 9: Scanner class exercise

Implement a ‘Scanner’ class data type,

‘scanner1’, so that Java asks for your height

in metres.

72Marius Claassen

Java, The Basics

Lecture 9: Scanner class exercise

73

public class Lecture10 {

public static void main(String[] args) {

System.out.print(“You are ” + height + “ m”);

System.out.print(“What is your height? ”);

// TODO: Implement double, as ‘height’

// TODO: Implement Scanner, as ‘scanner1’

}

}

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion74

Marius Claassen

Java, The Basics

Lecture 9: Scanner class exercise

Implement a ‘Scanner’ class data type,

‘scanner1’, so that Java asks for your height

in metres.

75Marius Claassen

Java, The Basics

import java.util.Scanner;

76

double height = scanner1.nextDouble();

Scanner scanner1 = new Scanner(System.in);

Marius Claassen

Java, The Basics

Lecture 10: Scanner class solution

77

public class Lecture10 {

public static void main(String[] args) {

System.out.print(“You are ” + height + “ m”);

System.out.print(“What is your height? ”);

// TODO: Implement double, as ‘height’

// TODO: Implement Scanner, as ‘scanner1’

}

}

Marius Claassen

Java, The Basics

78

public class Lecture10 {

public static void main(String[] args) {

System.out.print(“You are ” + height + “ m”);

System.out.print(“What is your height? ”);

}

}

Marius Claassen

Java, The Basics

import java.util.Scanner;

79

public class Lecture10 {

public static void main(String[] args) {

System.out.print(“You are ” + height + “ m”);

System.out.print(“What is your height? ”);

double height = scanner1.nextDouble();

Scanner scanner1 = new Scanner(System.in);

}

}

Marius Claassen

Java, The Basics

import java.util.Scanner;

80

public class Lecture10 {

public static void main(String[] args) {

System.out.print(“You are ” + height + “ m”);

System.out.print(“What is your height? ”);

double height = scanner1.nextDouble();

Scanner scanner1 = new Scanner(System.in);

}

} // What is your height?

Marius Claassen

Java, The Basics

import java.util.Scanner;

81

public class Lecture10 {

public static void main(String[] args) {

System.out.print(“You are ” + height + “ m”);

System.out.print(“What is your height? ”);

double height = scanner1.nextDouble();

Scanner scanner1 = new Scanner(System.in);

}

} // What is your height? 1,65

Marius Claassen

Java, The Basics

import java.util.Scanner;

82

public class Lecture10 {

public static void main(String[] args) {

System.out.print(“You are ” + height + “ m”);

System.out.print(“What is your height? ”);

double height = scanner1.nextDouble();

Scanner scanner1 = new Scanner(System.in);

}

} // What is your height? 1,65

// You are 1.65 mMarius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion83

Marius Claassen

Java, The Basics

Lecture 11: Ternary example

‘Ternary’ operator problem statement:

Implement the ‘Ternary’ operator where

‘grade’ is 74 and ‘result’ is a String. Print out

‘Pass’ if result >= 60 and ‘Fail’ otherwise.

84Marius Claassen

Java, The Basics

85

String result = (grade >= 60) ? “Pass” : “Fail”;

Marius Claassen

Java, The Basics

86

public class Lecture11 {

public static void main(String[] args) {

}

int grade = 74;

System.out.print(result);

// TODO: Implement String, ‘result’ Pass/Fail

}

Marius Claassen

Java, The Basics

87

public class Lecture11 {

public static void main(String[] args) {

}

int grade = 74;

System.out.print(result);

}

Marius Claassen

Java, The Basics

88

public class Lecture11 {

public static void main(String[] args) {

}

int grade = 74;

System.out.print(result);

String result = (grade >= 60) ? “Pass” : “Fail”;

}

Marius Claassen

Java, The Basics

89

public class Lecture11 {

public static void main(String[] args) {

}

int grade = 74;

System.out.print(result);

String result = (grade >= 60) ? “Pass” : “Fail”;

}

// PassMarius Claassen

Java, The Basics

Lecture 11: Ternary exercise

Implement the ‘Ternary’ operator where

‘wages’ are 3700 and ‘earnings’ are a String.

Print out ‘Exempt’ if earnings < 4500 and

‘Taxable’ otherwise.

90Marius Claassen

Java, The Basics

Lecture 11: Ternary exercise

91

public class Lecture12 {

public static void main(String[] args) {

System.out.print(earnings);

double wages = 3700;

// TODO: Implement the ternary operator

}

}

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion92

Marius Claassen

Java, The Basics

Lecture 11: Ternary exercise

Implement the ‘Ternary’ operator where

‘wages’ are 3700 and ‘earnings’ are a String.

Print out ‘Exempt’ if earnings < 4500 and

‘Taxable’ otherwise.

93Marius Claassen

Java, The Basics

94

: “Taxable”;

String earnings = (wages < 4500) ? “Exempt”

Marius Claassen

Java, The Basics

Lecture 11: Ternary exercise

95

public class Lecture12 {

public static void main(String[] args) {

System.out.print(earnings);

double wages = 3700;

// TODO: Implement the ternary operator

}

}

Marius Claassen

Java, The Basics

Lecture 12: Ternary solution

96

public class Lecture12 {

public static void main(String[] args) {

System.out.print(earnings);

double wages = 3700;

}

}

Marius Claassen

Java, The Basics

97

public class Lecture12 {

public static void main(String[] args) {

System.out.print(earnings);

double wages = 3700;

: “Taxable”;

String earnings = (wages < 4500) ? “Exempt”

}

}

Marius Claassen

Java, The Basics

98

public class Lecture12 {

public static void main(String[] args) {

System.out.print(earnings);

double wages = 3700;

: “Taxable”;

String earnings = (wages < 4500) ? “Exempt”

}

}

// ExemptMarius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion99

Marius Claassen

Java, The Basics

Lecture 13: stream() example

‘stream()’ method problem statement:

Implement the ‘stream()’ method to print a list

of integers.

100Marius Claassen

Java, The Basics

101

.forEach(i -> System.out.print(i + “ ”) );

integers.stream()

Marius Claassen

Java, The Basics

import java.util.List;

102

public class Lecture13 {

public static void main(String[] args) {

}

List<Integer> integers = List.of(6, 7, 8, 9, 10);

// TODO: Implement the ‘stream()’

}

Marius Claassen

Java, The Basics

import java.util.List;

103

public class Lecture13 {

public static void main(String[] args) {

}

List<Integer> integers = List.of(6, 7, 8, 9, 10);

}

Marius Claassen

Java, The Basics

import java.util.List;

104

public class Lecture13 {

public static void main(String[] args) {

}

List<Integer> integers = List.of(6, 7, 8, 9, 10);

.forEach(i -> System.out.print(i + “ ”) );

integers.stream()

}

Marius Claassen

Java, The Basics

import java.util.List;

105

public class Lecture13 {

public static void main(String[] args) {

}

List<Integer> integers = List.of(6, 7, 8, 9, 10);

.forEach(i -> System.out.print(i + “ ”) );

integers.stream()

}

// 6 7 8 9 10Marius Claassen

Java, The Basics

Lecture 13: stream() exercise

Implement the ‘stream()’ method to print the

names of the ‘BRICS’ countries.

106Marius Claassen

Java The Basics

Lecture 13: stream() exercise

107

public class Lecture14 {

public static void main(String[] args) {

List<String> brics = List.of(“Brazil”, “Russia”,

// TODO: Implement the ‘stream()’

“India”, “China”, “South Africa”);

}

}

Marius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion108

Marius Claassen

Java, The Basics

Lecture 13: stream() exercise

Implement the ‘stream()’ method to print the

names of the ‘BRICS’ countries.

109Marius Claassen

Java, The Basics

110

.forEach(c -> System.out.print(c + “ ”) );

brics.stream()

Marius Claassen

Java, The Basics

Lecture 13: stream() exercise

111

public class Lecture14 {

public static void main(String[] args) {

List<String> brics = List.of(“Brazil”, “Russia”,

// TODO: Implement the ‘stream()’

“India”, “China”, “South Africa”);

}

}

Marius Claassen

Java, The Basics

import java.util.List;

112

public class Lecture14 {

public static void main(String[] args) {

List<String> brics = List.of(“Brazil”, “Russia”,

// TODO: Implement the ‘stream()’

“India”, “China”, “South Africa”);

}

}

Marius Claasse,

Java, The Basics

import java.util.List;

113

public class Lecture14 {

public static void main(String[] args) {

List<String> brics = List.of(“Brazil”, “Russia”,

“India”, “China”, “South Africa”);

}

}

Marius Claasse,

Java, The Basics

import java.util.List;

114

public class Lecture14 {

public static void main(String[] args) {

.forEach(c -> System.out.print(c + “ ”) );

List<String> brics = List.of(“Brazil”, “Russia”,

brics.stream()

“India”, “China”, “South Africa”);

}

}

Marius Claassen

Java, The Basics

import java.util.List;

115

public class Lecture14 {

public static void main(String[] args) {

.forEach(c -> System.out.print(c + “ ”) );

List<String> brics = List.of(“Brazil”, “Russia”,

brics.stream()

“India”, “China”, “South Africa”);

}

}

// Brazil Russia India China South AfricaMarius Claassen

Java, The Basics

TOPICS:

Introduction

Hello World

Primitive Data Types

Reference Data Types

The Scanner Class

The Ternary Operator

The Stream() Method

Conclusion116

Marius Claassen

Java, The Basics

Lecture 15: Project

Project problem statement:

The following names appear in a list: Enos,

Mahalaleel, Adam, Seth, Cainan.

Implement the ‘stream()’ method to sort and

print these names in alphabetical order.

117Marius Claassen

Java, The Basics

Lecture 15: Final remarks

118Marius Claassen

Java, The Basics

To access this course:

• https://www.udemy.com/course/1435298/manage/basics/

and

• http://skl.sh/2hGOtbV

or

• mariusclaassen@gmail.com

119Marius Claassen

Java, The Basics

Java, The BasicsStart coding using Java

Marius Claassen

Java, The Basics