Why does having [].map with curly brackets change the way it works?

Question

So, basically I have this:

Array.prototype.toString = function() {
    return (\"[\" + this.map(thing => thing = \'\"\' + thing + \'\"\').join(\', \') + \"]\"         


        

Answer 1

Without curly braces (or with regular curved brackets) it returns a single value straight up, whereas curly braces execute multiple lines of code. If you want this code to return a value you have to explicitly return it within those curly braces.