How to simulate enumeration with JS

Preface

In current JavaScript, there is no concept of enumeration. In some scenarios, using enumeration can better ensure the correctness of data and reduce the data verification process. The following introduces how JavaScript can simulate the enumeration effect.

Enumeration main features

• Enumeration values ​​cannot be repeated
• Cannot be modified

accomplish

let days;
(function (days) {
    days[days["Sunday"] = 0] = "Sunday";
    days[days["Monday"] = 1] = "Monday";
    days[days["Tuesday"] = 2] = "Tuesday";
    days[days["Wednesday"] = 3] = "Wednesday";
    days[days["Thursday"] = 4] = "Thursday";
    days[days["Friday"] = 5] = "Friday";
    days[days["Saturday"] = 6] = "Saturday";
})(days || (days = {}));

At this point, the days object basically implements the enumeration effect. You can access the days object through the enumeration value or index, but an important feature of the enumeration is that it cannot be modified. At this point, days can be modified at will; you can use the Object.freeze function to prevent the object from being modified and re-export an unmodifiable object. The complete code is as follows:

let days;
(function (days) {
    days[days["Monday"] = 1] = "Monday";
    days[days["Tuesday"] = 2] = "Tuesday";
    days[days["Wednesday"] = 3] = "Wednesday";
    days[days["Thursday"] = 4] = "Thursday";
    days[days["Friday"] = 5] = "Friday";
    days[days["Saturday"] = 6] = "Saturday";
    days[days["Sunday"] = 0] = "Sunday";
})(days || (days = {}));

//Export enumerable object export EnumWeek = Object.freeze(days)

The above is the details of how to use JS to simulate enumeration. For more information about JS, please pay attention to other related articles on 123WORDPRESS.COM!