Can check for JS object value be replaced with a ternary?

user_362437 0
Viewed 34

I have an API that returns objects in JSON. Not all of them have the same fields, some have a few more. I am populating a table, and want a cleaner way to do the following:

if (items.hasOwnProperty('dayMargin')) {
    var dayMargin = items.dayMargin.formattedValue;
} else {
    var dayMargin = "--"
}

So if that object has 'dayMargin' it will either output the value, or "--" if that key / value doesn't exist. I want to clean this up, as there are 10+ similar scenarios. Is it possible to use a ternary operator here? If so, how?

conditional-operator javascript
3 Answers
var dayMargin = items.hasOwnProperty('dayMargin') ? items.dayMargin.formattedValue : "--";

You could also use conditional chaining and the null coalescing operator:

var dayMargin = items?.dayMargin.formattedValue ?? "--";
user_14918950

Im not sure If i understand your problem, however you can create a ternary oparator like this:

const dayMargin = items.hasOwnProperty('dayMargin') ? items.dayMargin.formattedValue : '--'
user_78590230

The null coalescing operator is used to do exactly what you want.

//Object formating example
let items = {
  dayMargin: 'im here',
}
items.dayMargin = items.dayMargin ?? '--'
items.nightMargin = items.nightMargin ?? '--'
console.log(items)

//Property extracting example
let items2 = {
  dayMargin: {formatedValue:'im here'},
}
const dayMargin = items2.dayMargin?.formatedValue ?? '--'
const nightMargin = items2.nightMargin?.formatedValue ?? '--'
console.log(dayMargin, nightMargin)

user_168211090
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