Java Tutorial for Complete Beginners, by John Purcell

Section 1 : Introduction

• Chapter 1 : Introduction and installation
• Chapter 2 : What Java is and how it works ?
• Chapter 3 : Getting a job and what to study after completing ?
• Chapter 4 : How to get The most out of this course

Section 2 : Programming Core Java

• Chapter 5 : A Hello World program
• Chapter 6 : Using variables
• Chapter 7 : Strings: working with text
• Chapter 8 : While loops
• Chapter 9 : For loops

Section 3 : The Java Collections Framework

Section 5 : What's New In Java 8 ?

Additional notes

These notes are based on the Oracle Java SE Tutorial.

About chapter 6

Notes on this chapter are based on Variables and Primitive_Data_Types Java SE Tutorial.

• Java defines the following kinds of variables:
  • Instance variables
  • Class variables
  • Local variables
  • Parameters
• Uses the Camel Case convention for naming Java variables except for the ones storing constant value, where we use Screaming Snake Case convention.
• Java supports eight (08) primitive data types :
  • byte : an 8-bit signed two's complement integer
  • short : an 16-bit signed two's complement integer
  • int : an 32-bit signed two's complement integer
  • long : an 64-bit signed two's complement integer
  • float : a single-precision 32-bit IEEE 754 floating point; should never be used for precise values, such as currency
  • double : a single-precision 64-bit IEEE 754 floating point; generally the default choice for decimal values; should never be used for precise values, such as currency
  • boolean : has only two possible values : true and false
  • char : a single 16-bit Unicode character
• Special escape sequences for char are:
  • \b (backspace)
  • \t (tab)
  • \n (line feed)
  • \f (form feed)
  • \r (carriage return)
  • \" (double quote)
  • \' (single quote)
  • \\ (backslash)

About chapter 7

Notes on this chapter are based on Strings Java SE Tutorial.

• String class has 13 constructors, allowing to provide the initial value of the string using different sources.
• String objects are immutable, which means that once created, their values cannot be changed.
• List of some String methods signature :
  • public int length()
  • public char charAt(int index)
  • public String concat(String str)
• The + operator is the most used for concatenation. And such a concatenation can be mixture of any objects. So, for each object that is not a String, its toString() method is called to convert it to a String.