• String 
• stores text, such as “Hello”. String values are surrounded by double quotes
• int 
• stores integers (whole numbers), without decimals, such as 123 or -123
• float 
• stores floating point numbers, with decimals, such as 19.99 or -19.99
• char 
• stores single characters, such as ‘a’ or ‘B’. Char values are surrounded by single quotes
• boolean 
• stores values with two states: true or false

Declaring a variable

type variableName = value;

• Here, ‘=’ is used to assign values to the variables

Identifiers

• All Java variables must be identified with unique names
• Mostly can be short names but preferred descriptive names for understandability and to maintain code

[! Rules for variables]

• Names can contain letters, digits, underscores, and dollar signs

• Names must begin with a letter

• Names should start with a lowercase letter and it cannot contain whitespace

• Names can also begin with $ and _ (but we will not use it in this tutorial)

• Names are case sensitive (“myVar” and “myvar” are different variables)

• Reserved words (like Java keywords, such as int or boolean) cannot be used as names