- Numbers
- Integer Types
- Floating Types
- Other
- Characters
- Strings
- Boolean
Integer Types -> Store whole numbers (no decimals). These can be positive or negative.
Floating Types -> Store numbers with a fractional part (decimals).
Characters -> Used to store single characters.
Strings -> Stores a sequence of characters. A string of text longer than one character.
Boolean -> Stores a true or false variable.
Integer types are positive or negative whole numbers (without decimals).
-Bytes store whole numbers from -128 to 127.
-They take up the least memory space (a single byte).
-The default value of a byte is 0.
-Ex: byte example = 100;
-Shorts store whole numbers from -32,768 to 32,767
-They take up the second least memory space (two bytes)
-The default value of a short is 0.
-Ex: short example = -300;
-The most commonly used integer data type. You should be using these in most of the code you write, unless you have a specific reason to want to save space.
-Integers store values from -2,147,483,648 to 2,147,483,647.
-Every integer takes up 4 bytes of space.
-Ex: int example = 20;
-Stores values from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.
-Used only when a number larger than an integer is needed.
-Every long takes up 8 bytes of space.
-Values should end with an L.
-Ex: long example = 100000L;.
Floating types are positive or negative numbers with a fractional part.
-All values should end with an f.
-Default value is 0.0f.
-Takes up 4 bytes of space.
-Ex: float example = 1.0f;
-The most commonly used floating data type. You should be using these in most of the code you write, unless you have a specific reason for using another.
-Takes up 8 bytes of space.
-Ex: double example = 3.05;
-Can only take two values: true and false
-Ex: boolean example = true;
-Takes up 1 bit of space
-Can be replaced with a boolean expression. A boolean expression is something that evaluates to either true or false.
-Ex: 7 < 8 evaluates to true.
-Used to store a single alphanumeric character.
-Must be surrounded by single quotes '.
-ASCII characters can also be printed out.
-Ex: char a = 65; prints out to A.
-Takes up 2 bytes of space.
-Used to store a sequence of characters. Composed of text.
-Must be surrounded by double quotes.
-Called the "special ninth type" in Java because it is used so often.
-Actually a non-primitive data type (functions as an object) but is often listed as primitive
-String is a type of object, not a primitive data-type.
-Ex: String example = "example";