Enums in TypeScript

Harsh ChandwaniHarsh Chandwani
2 min read

Here is the typescript file where I have compared enums with types

//Okay now lets do this
//basically when want to have a function, that should only some particular values, and it will be string
//one option is to create a if statment that can handle unknown situations (string)
//other people use in typescript is type


type keyInput = "up" | "down" | "left" | "right";

function doSomething(keyPressed: keyInput){
    //do something
    if(keyPressed == "up"){
        console.log(keyPressed);
    }

}

doSomething("up");
doSomething("down");


/*
but what are enums, (they are more human-readable, that why we use, and that will make us understand other
developer code to be much easier and readable)
*/

//here are the enums
enum Direction {
    Up, 
    Down, 
    Right, 
    Left
}

function doSomething1(keyPressed: Direction){
    //so something
    if(keyPressed == Direction.Up){
        console.log(Direction.Up);
    }
}


doSomething1(Direction.Right);

And here is how the .js file has came up

"use strict";
//Okay now lets do this
//basically when want to have a function, that should only some particular values, and it will be string
//one option is to create a if statment that can handle unknown situations (string)
//other people use in typescript is type
function doSomething(keyPressed) {
    //do something
    if (keyPressed == "up") {
        console.log(keyPressed);
    }
}
doSomething("up");
doSomething("down");
/*
but what are enums, (they are more human-readable, that why we use, and that will make us understand other
developer code to be much easier and readable)
*/
//here are the enums
var Direction;
(function (Direction) {
    Direction[Direction["Up"] = 0] = "Up";
    Direction[Direction["Down"] = 1] = "Down";
    Direction[Direction["Right"] = 2] = "Right";
    Direction[Direction["Left"] = 3] = "Left";
})(Direction || (Direction = {}));
function doSomething1(keyPressed) {
    //so something
    if (keyPressed == Direction.Up) {
        console.log(Direction.Up);
    }
}
doSomething1(Direction.Right);

Hope you understand the difference and go on with your typescript journey.

Thank you

Harsh Chandwani

Software Developer

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Written by

Harsh Chandwani
Harsh Chandwani

Software Dev | 22 Years Old | Final Year Student | MERN Developer | GDSC Technical Core Member | ex- GeeksforGeeks | Writer | Poet |