# Data types

Note that the host application may add types specific to that application, refer to the application's manual for more information.

- void
- bool
- int, int8, int16, int64
- uint, uint8, uint16, uint64
- float
- double
- Arrays
- Object handles
- Strings

## void

`void` is not really a data type, more like lack of data type. It can only be used to tell the compiler that a function doesn't return any data.

## bool

`bool` is a boolean type with only two possible values: `true` or `false`. The keywords `true` and `false` are constants of type `bool` that can be used as such in expressions.

## int, int8, int16, int64

`int64` holds integer values in the range -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

`int` holds integer values in the range -2,147,483,648 to 2,147,483,647.

`int16` holds integer values in the range -32,768 to 32,767.

`int8` holds integer values in the range -128 to 128.

As the scripting engine has been optimized for 32 bit datatypes, using the smaller variants is only recommended for accessing application specified variables. For local variables it is better to use the 32 bit variant.

`int32` is an alias for `int`.

## uint, uint8, uint16, uint64

`uint64` holds integer values in the range 0 to 18,446,744,073,709,551,615.

`uint` holds integer values in the range 0 to 4,294,967,295.

`uint16` holds integer values in the range 0 to 65,535.

`uint8` holds integer values in the range 0 to 255.

As the scripting engine has been optimized for 32 bit datatypes, using the smaller variants is only recommended for accessing application specified variables. For local variables it is better to use the 32 bit variant.

`uint32` is an alias for `uint`.

## float

`float` holds real (or floating point) values in the range -/+3.402823466e38.

The smallest possible positive number that a float can destinguish is: 1.175494351e-38. The maximum number of decimal digits that can be safely used is 6, i.e. if more digits are used they are prone to rounding errors during operations.

Curiousity: Floats may also have the additional values of positive and negative 0 or infinite, and NaN (Not-a-Number). NaN is represented by the 32 bit data word 0x7fc00000.

## double

`double` holds real (or floating point) values in the range -/+1.7976931348623158e+308.

The smallest possible positive number that a double can destinguish is: 2.2250738585072014e-308. The maximum number of decimal digits that can be safely used is 15, i.e. if more digits are used they are prone to rounding errors during operations.

Curiousity: Doubles may also have the additional values of positive and negative 0 or infinite, and NaN (Not-a-Number).

## Arrays

It is also possible to declare array variables by appending the [] brackets to the type.

When declaring a variable with a type modifier, the type modifier affects the type of all variables in the list. Example:

      int[] a, b, c;

`a`, `b`, and `c` are now arrays of integers.

When declaring arrays it is possible to define the initial size of the array by passing the length as a parameter to the constructor. The elements can also be individually initialized by specifying an initialization list. Example:

      int[] a;           // A zero-length array of integers
      int[] b(3);        // An array of integers with 3 elements
      int[] c = {,3,4,}; // An array of integers with 4 elements, where
                         // the second and third elements are initialized

Each element in the array is accessed with the indexing operator. The indices are zero based, i.e the range of valid indices are from 0 to length - 1.

      a[0] = some_value;

An array also have two methods. length() allow you to determine how many elements are in the array, and resize() lets you resize the array.

## Object handles

Object handles are a special type that can be used to hold references to other objects. When calling methods or accessing properties on a variable that is an object handle you will be accessing the actual object that the handle references, just as if it was an alias. Note that unless initialized with the handle of an object, the handle is `null`.

      obj o;
      obj@ a;           // a is initialized to null
      obj@ b = @o;      // b holds a reference to o

      b.ModifyMe();     // The method modifies the original object

      if( a is null )   // Verify if the object points to an object
      {
        @a = @b;        // Make a hold a reference to the same object as b
      }

Not all types allow a handle to be taken. Neither of the primitive types can have handles, and there may exist some object types that do not allow handles. Which objects allow handles or not, are up to the application that registers them.

Object handle and array type modifiers can be combined to form handles to arrays, or arrays of handles, etc.

## Strings

Strings are a special type of data that can be used only if the application registers support for them. They hold an array of bytes. The only limit to how large this array can be is the memory available on the computer.

There are two types of string constants supported in the AngelScript language, the normal double quoted string, and the documentation strings, called heredoc strings.

The normal strings are written between double quotation marks (`"`) or single quotation marks (`'`)1. Inside the constant strings some escape sequences can be used to write exact byte values that might not be possible to write in your normal editor.

sequence | value | description
`\0` | 0 | null character
`\\` | 92 | back-slash
`\'` | 39 | single quotation mark (apostrophe)
`\"` | 34 | double quotation mark
`\n` | 10 | new line feed
`\r` | 13 | carriage return
`\t` | 9 | tab character
`\xFF` | 0xFF | FF should be exchanged for the hexadecimal number representing the byte value wanted

      string str1 = "This is a string with \"escape sequences\".";
      string str2 = 'If single quotes are used then double quotes can be included without "escape sequences".';

The heredoc strings are designed for inclusion of large portions of text without processing of escape sequences. A heredoc string is surrounded by triple double-quotation marks (`"""`), and can span multiple lines of code. If the characters following the start of the string until the first linebreak only contains white space, it is automatically removed by the compiler. Likewise if the characters following the last line break until the end of the string only contains white space this is also remove, including the linebreak.

      string str = """
      This is some text without "escape sequences". This is some text.
      This is some text. This is some text. This is some text. This is
      some text. This is some text. This is some text. This is some
      text. This is some text. This is some text. This is some text.
      This is some text.
      """;

If more than one string constants are written in sequence with only whitespace or comments between them the compiler will concatenate them into one constant.

      string str = "First line.\n"
                   "Second line.\n"
                   "Third line.\n";

1) The application can change the interpretation of single quoted strings by setting an engine property. If this is done the first character in the single quoted string will be interpreted as a single uint8 value instead of a string literal.