var a = "the letter a";
var obj = {};
obj.brovo = "the letter b";
obj.charlie = "the letter c";
if (!obj.alpha) obj.alpha = a;
Since I wish to use this at different points in my code and will be using it multiple times I wish for it to be used as the following:
isNotSet(obj.alpha, a);
I wish this to equate obj.alpha = a;
I started with the following function:
function isNotSet (arg1, arg2) {
if (!arg1) arg1 = arg2;
return arg1;
}
The solution is really just a simple one-liner:
obj.alpha = obj.alpha || a;
If you really need a function, you can wrap it:
function isNotSet(obj, arg1, arg2) {
obj[arg1] = obj[arg1] || arg2;
}
You should be aware, though, that both this solution and your proposed solution will overwrite the value if obj[arg1] is set to false (or any other falsy value).
If you want to handle those values properly, the easiest way would be:
function isNotSet(obj, arg1, arg2) {
if(typeof obj[arg1] !== "undefined" && obj[arg1] !== null) { return; }
obj[arg1] = arg2;
}
null and undefined. Still doesn't check property ownership.
I was able to accomplish this with the following function:
isNotSet('alpha', a);
I just take the arg1 as just the Property Name then add it to the object then assign the value to that object with the Property Name.
function isNotSet (arg1, arg2) {
if (!obj[arg1]) obj[arg1] = arg2;
}
obj in your code.
hasOwnProperty instead of !obj[arg1] but that depends on how you wont to handle null, undefined, 0, false and empty string.