How to use ES6 Symbols In Javascript

Q: How to use ES6 Symbols In Javascript

We firstly create an object TShirtSizesInside the object, we define symbols for each size using Symbol()The orderTShirt function takes a size argument.We had performed a strict comparison (!==) between the argument and each enum member (symbol) to ensure a valid size is provided.If a valid size is used, then the order is been processed.If anyone attempt to use an invalid string value (e.g. “Medium”) throws an error due to the strict comparison with symbols.

Using Object Literal with Object.freeze()

Using Closures

We firstly create an object TShirtSizes
Inside the object, we define symbols for each size using Symbol()
The orderTShirt function takes a size argument.
We had performed a strict comparison (!==) between the argument and each enum member (symbol) to ensure a valid size is provided.
If a valid size is used, then the order is been processed.
If anyone attempt to use an invalid string value (e.g. “Medium”) throws an error due to the strict comparison with symbols.

Example: This example shows how to create an enum using ES6 Symbols.

Javascript


                    const TShirtSizes = {
    SMALL: Symbol('Small'),
    MEDIUM: Symbol('Medium'),
    LARGE: Symbol('Large'),
    EXTRA_LARGE: Symbol('Extra Large')
};

function orderTShirt(size) {
    if (size !== TShirtSizes.SMALL &&
        size !== TShirtSizes.MEDIUM &&
        size !== TShirtSizes.LARGE &&
        size !== TShirtSizes.EXTRA_LARGE) {
        throw new Error('Invalid T-Shirt size!');
    }

    console.log(`Processing order for
      size: ${String(size)}`);
}

orderTShirt(TShirtSizes.MEDIUM);

Output

Processing order for
      size: Symbol(Medium)

Let’s see if we try to provide a string argument:

Javascript


                    const TShirtSizes = {
    SMALL: Symbol('Small'),
    MEDIUM: Symbol('Medium'),
    LARGE: Symbol('Large'),
    EXTRA_LARGE: Symbol('Extra Large')
};

function orderTShirt(size) {
    if (size !== TShirtSizes.SMALL &&
        size !== TShirtSizes.MEDIUM &&
        size !== TShirtSizes.LARGE &&
        size !== TShirtSizes.EXTRA_LARGE) {
        throw new Error('Invalid T-Shirt size!');
    }

    console.log(`Processing order for 
    size: ${String(size)}`);
}


orderTShirt("Medium");

Output:

How to Create Enums in JavaScript ?

An enum, short for “enumerated type”, is a special data type in programming languages that allows us to define a set of named constants. These constants are essentially unchangeable variables that represent a fixed collection of possible values. Each contants can be accessed by its name. Enums are very similar to constants but they offer more data structure. we will learn about creating enums in JavaScript, exploring their significance in code organization and readability, along with practical implementation approaches using closures and other techniques.

These are the following approaches: