Java is a popular programming language, created in 1995.

It is owned by Oracle, and more than 3 billion devices run Java.

Data types are divided into two groups:

• Primitive data types - includes byte, short, int, long, float, double, boolean and char

• Non-primitive data types - such as String, Arrays and Classes

Type casting is when you assign a value of one primitive data type to another type.

In Java, there are two types of casting:

• Widening Casting (automatically) - converting a smaller type to a larger type size
  byte -> short -> char -> int -> long -> float -> double
  
  

• Narrowing Casting (manually) - converting a larger type to a smaller size type
  double -> float -> long -> int -> char -> short -> byte

Operators are used to perform operations on variables and values.

Java has the following conditional statements:

• Use if to specify a block of code to be executed, if a specified condition is true

• Use else to specify a block of code to be executed, if the same condition is false

• Use else if to specify a new condition to test, if the first condition is false

• Use switch to specify many alternative blocks of code to be executed

Loops can execute a block of code as long as a specified condition is reached.

Loops are handy because they save time, reduce errors, and they make code more readable.