Kotlin - Collections Fundamentals
You want to create a list of strings that you can add items to later. Which Kotlin code correctly creates this list and adds "orange" to it?
You want to create a list of strings that you can add items to later. Which Kotlin code correctly creates this list and adds "orange" to it?
hard📝 Application Q15 of 15
Step-by-Step Solution
Solution:
Step 1: Choose a mutable list
To add items later, the list must be mutable, so usemutableListOf.Step 2: Use add() method correctly
Callingadd("orange")on a mutable list adds the item successfully.Step 3: Check other options
val fruits = listOf("apple", "banana") fruits.add("orange") tries to add to immutable list (error). val fruits = listOf("apple", "banana") fruits += "orange" uses += on immutable list (creates new list but does not modify original). val fruits = mutableListOf("apple", "banana") fruits = fruits + "orange" tries to reassign val which is not allowed.Final Answer:
val fruits = mutableListOf("apple", "banana") fruits.add("orange") -> Option DQuick Check:
Mutable list + add() = correct way [OK]
Quick Trick: Use mutableListOf and add() to change list after creation [OK]
Common Mistakes:
MISTAKES- Adding to immutable list
- Trying to reassign val variable
- Using += on immutable list expecting mutation
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