Other 4 Small Javascript things I did not know until today

DanielSeptember 10, 2021September 12, 2021

Some while ago I've written this article Small Javascript things I did not know until today. Meanwhile, I've discovered a few more small Js tips I would like to share with you:

1. If you have a return statement in a finally block it will overwrite other returns

function thisFunctionReturnsB() {
    try {
        throw new Error( 'Foo' );
    } catch( e ) {
        return 'A';
    } finally {
        return 'B';
    }
}

More details in this article written by Jake Archibald.

2. We can use numbers separators to improve readability

const myFirstMillion = 1_000_000;
console.log(myFirstMillion); // 1000000

3. The default case does not need to be last in a switch statement

Even if we see the default as the last option in a switch case, and somehow is also a bit logical to put it so, also the following is a valid syntax:

switch (foo) {
    case 1:
        // do something...
        break;
    default:
        // do something...
        break;
    case 3:
        // do something...
        break;
}

More details here.

Btw, you can also match multiple values in a switch statement.

4. Easily convert from a string to string to a number

const str = '404';
console.log(+str) // 404;  

Before I was using the parseInt function.