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kotlinlang

Hey guys, Can we optimise or idiotmatic way this code ?
```internal fun combineFullName(customerAddress: CustomerAddress?): CustomerAddress? {
    val fullName = if (customerAddress?.fullName.isNullOrEmpty()) {
        customerAddress?.firstName + " " + customerAddress?.lastName
    } else {
        customerAddress?.fullName
    }
    return customerAddress?.copy(fullName = fullName)
}```
Thanks

What is `fullName` in the `CustomerAddress` definition? Can it have a value that is not first+last? Or does it always start empty/null and is then set by this function?

`fullName`  is a type of String. It has 2 condition.
*1st Scenario* 
 `fullName` will be null then we need to set first+last.
*2nd Scenario*
`fullName` will not be null then we don't need to set first+last because it has same value in first and last.
Thanks

first+last is a bad idea. <https://www.kalzumeus.com/2010/06/17/falsehoods-programmers-believe-about-names/>

well, first point would be not passing _nullable_ `CustomerAddress` to the function, as it serves no purpose here. Instead you would be better of using it as a receiver
and turn any callsite of `combineFullName(someExpression)` to `someExpression?.combineFullName()` getting exact same results

After that it looks pretty good, with small change:
```internal fun CustomerAddress.combineFullName(): CustomerAddress {
    val fullName = if (fullName.isNullOrEmpty()) { 
        "$firstName $lastName"
    } else {
        fullName
    }
    return copy(fullName = fullName)
}```
And yes, it's a bad idea :stuck_out_tongue:

and it would probably make more sense as part of the construction of the class itself

Yeah it could just be a default value of `fullName`

<@UJQB4DJF7> actually I just write in short form first + last but in actual is `firstName + lastname` in my data class. Thanks for sharing that article. I'll remember in future

How can I do in the construction of class?

```data class Address(
    val first: String,
    val last: String,
    val full: String = "$first $last"
)

println(Address(first = "first", last = "last"))
println(Address(first = "first", last = "last", full = "weird full name"))```
Prints
```Address(first=first, last=last, full=first last)
Address(first=first, last=last, full=weird full name)```


Actually firstName, lastName and fullName is coming from server and it can null/empty that's why I used nullable

I chewed you out for using nullable argument for single argument function that does nothing and just returns `null` if it gets `null` - this is the purpose of `?.` operator, you don't really need to handle it in function

Not for individual fields :stuck_out_tongue: (and your above code currently does not really handle nullability... for example it would set fullName to `"null null"` if it got every field null, but you constructed a class from that)

In fact, I recently received a letter through the post, addressed as "Dear null". So this happens in production code too.