How does this JS sort when it has a function inside that returns multiple things?

I created a secondary sort and its working but I don’t understand how.

    this.report.sort((a, b) => {
        if(a[col] > b[col]) return 1;
        if(a[col] < b[col]) return -1;
        if(a[secondaryFilter] > b[secondaryFilter]) return  1;
        if(a[secondaryFilter] < b[secondaryFilter]) return -1;
    });

I thought when the sort sees the first return, it would exit the sort. How does it reach the secondary filter sort?

The code works and I learned the syntax online but I don’t get how it works.