I'm just wondering why should I use this method to return a function :
clusters.prototype.get_local_storage_data = function(data_key) {
return +(this.localStorage.getItem(data_key) || 1);
};
What does the +() do there and why using that ? Is there a better way of returning the function or 1 if what the function gets is null ?
Using the + before a value forces that value to become a number. In the case above, the data key will be converted to a number (if it's found), or the number 1 will be returned. Either way, the result will be converted to a number.
+null; // 0
+"3.14"; // 3.14
+1; // 1
It's just ensuring that no matter what the output is, you will be returning a number.
getItem returns a string: dev.w3.org/html5/webstorage/#storage-0JSON.parse() it is the same thing I stored. It might as well be an object or an array, because I'm using JSON.stringfy(). Or am I wrong ?
JSON.parse() on the returned string, you will also end up with a number.The + is there to cast the result to a number -
typeof +"123" // "number"
The way it's implemented looks just fine, and doesn't need to be changed.
The + is just making sure the return value is a number or else 1 would be true and not the number one. It's a shortcut for:
Number( expression )
