Literals

Description

A literal is a notation for representing a fixed value in source code. Almost all programming languages have notations for atomic values such as integers, floating-point numbers, and strings, booleans and characters.

Literals are often used to initialize variables, for example, in the following, '1' is an IntegerLiteral which is assigned to a new created variable 'a' of data type Integer. And the three letter string in "cat" is a StringLiteral, which is assigned to a new created variable 's' of data type String.

Integer a = 1;
String s = "cat";

Types

The following types of Literals exists

• Simple Data Type
• Container Data Type
• Complex Data Type

Simple Data Type

The following table lists all available literals for Simple Data Types:

Data Type	Literal	Sample
Boolean	{True|False}	Boolean flag = True;
Integer	Integer number	Integer n = 1; m = n - 1234;
Float	Floating-point number	Float n = 1.2; m = n + 12.345;
String	Quoted sequence of characters	String str = "This is a text" str = StringConcatenate(str, " definded as a literal in OTX.");
ByteField	Sequence of bytes in hex started with a &	ByteField bytes1 = &12 34 56 78 90 AB CD EF ByteField bytes2 = &1234567890ABCDE; // equals &01 23 45 67 89 0A BC DE

Container Data Type

The following table lists all available literals for Container Data Types:

Data Type	Literal	Sample
List	List one or more elements in braces seperated with comma	List<Integer> integerList = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; List<List<String>> stringList = { { "Text11", "Text12" }, { "Text21", "Text22", "Text23" }, { "Text31" } };
Map	List one or more key value pairs in braces seperated with comma; in each pair of key value, the key connects with the value by the equal sign	Map<String, Integer> myMap1 = { "Key1"=1234, "Key2"=567, "Key3"=89 }; Map<String, List<Integer>> myMap2 = { "Key1"={ 1, 2, 3, 4 }, "Key2"={ 5, 6, 7 }, "Key3"={ 8, 9 } };

Complex Data Type

Literals for Complex Data Type have the following syntax:

@DataTypeName:MemberValue1/MemberValue2/../MemberValueN

Where DataTypeName is the name of the related data type and MemberValue the value of the corresponding value. Sample:

// ResultStateLiteral for enumeration value POSITIVE
@ResultState:POSITIVE;

// UserExceptionLiteral to throw an user defined exception
@UserException:"FATAL_ERROR"/"There is a fatal error occured!";

// QuantityLiteral for a value of 1.2 %
@Quantity:1.2/"%"/1;