CODEWITHSUNDEEP
javascriptif-statementnested
ilarsona
ilarsona

Reputation: 436

"If" consolidation/avoiding nesting

I'm really trying to avoid nesting in this code snippet... 

deal_trade_in_model_1 = document.getElementById('deal_trade_in_model_1').value;
deal_trade_in_amount_1 = document.getElementById('deal_trade_in_amount_1').value;
if (typeof deal_trade_in_model_1 !== 'undefined' && deal_trade_in_model_1 !== null) {
    console.log(deal_trade_in_amount_1);
    console.log(deal_trade_in_model_1);
        if (deal_trade_in_model_1 !== null || deal_trade_in_model_1 !== "") {
            if (deal_trade_in_amount_1 == null || deal_trade_in_amount_1 == "") {
                console.log('entered into function');
                document.getElementById("deal_trade_in_model_1").value = "";
                document.getElementById("deal_trade_in_amount_1").value = "";
    }
}
}

Basically, what this function does is take the value of two fields... things to know about them and what I want to do to them:

1) They're NOT required

2) If one of them is filled out, the other must be

3) If ONLY one of them is filled out, the user clicks submit, and this part of the function is called upon, I want to delete the value of both of them.

I've tried doing a compound of

&& (and)

and

|| (or)

buttttt it odiously it didn't work.

Primary question: What's the best way to get rid of the nesting (I planned on doing this twice and just swapping the code) that will be the most efficient? This, I want, to be done preferably in the smallest amount of IF statements possible.

Please note: If you change the code a lot, I might not know what you're talking about.. please be prepared to teach me or help me learn!

Upvotes: 1

Views: 76

Answers (1)

Felix Kling
Felix Kling

Reputation: 816364

It sounds like you only want to do something if either of the fields are empty, but not both. Assuming both of the elements are text fields, .value will always return a string. Converting a string to boolean results in false if the string is empty, otherwise true.

So

Boolean(deal_trade_in_model_1) === Boolean(deal_trade_in_amount_1)

will be true if either both fields have a value (both will convert to true) or both fields are empty (both convert to false).

Thus your code can be reduced to

var model_1 = document.getElementById('deal_trade_in_model_1');
var amount_1 = document.getElementById('deal_trade_in_amount_1');

if (Boolean(model_1.value) !== Boolean(amount_1.value)) {
    model_1.value = "";
    amount_1.value = "";
}

Upvotes: 1

Related Questions