JavaScript Mapping for Constants

Here are the sample constant definitions once more:

Slice

module Example
{
    const bool      AppendByDefault = true;
    const byte      LowerNibble = 0x0f;
    const string    Advice = "Don't Panic!";
    const short     TheAnswer = 42;
    const double    PI = 3.1416;
    
    enum Fruit { Apple, Pear, Orange }
    const Fruit     FavoriteFruit = Pear;
}

For each constant, the JavaScript mapping generates a read-only property of the same name in the enclosing scope as shown below:

JavaScript

Object.defineProperty(Example, 'AppendByDefault', {value: true});
Object.defineProperty(Example, 'LowerNibble', {value: 15});
Object.defineProperty(Example, 'Advice', {value: "Don't Panic!"});
Object.defineProperty(Example, 'TheAnswer', {value: 42});
Object.defineProperty(Example, 'PI', {value: 3.1416});
Object.defineProperty(Example, 'FavoriteFruit', {value: Fruit.Pear});

TypeScript

const AppendByDefault:boolean;
const LowerNibble:number;
const Advice:string;
const TheAnswer:number;
const PI:number;
const FavoriteFruit:Fruit;

Slice string literals that contain non-ASCII characters or universal character names are mapped to JavaScript string literals with universal character names. For example:

Slice

const string Egg = "œuf";
const string Heart = "c\u0153ur";
const string Banana = "\U0001F34C";

is mapped to:

JavaScript

Object.defineProperty(Example, 'Egg', {value: "\u0153uf"});
Object.defineProperty(Example 'Heart', {value: "c\u0153ur"});
Object.defineProperty(Example, 'Banana', {value: "\ud83c\udf4c"});

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See Also