[Solved] What is the issue with the following Kotlin code?val numbers = listOf(10, 20, 30) numbers.add(40) — Ans: listOf() creates an immutable list, so add() is not allowed | Kotlin

Kotlin - Collections Fundamentals

What is the issue with the following Kotlin code?

val numbers = listOf(10, 20, 30)
numbers.add(40)

AThe list must be declared with var instead of val

BThe add() method requires an index parameter

ClistOf() creates an immutable list, so add() is not allowed

DThe listOf() function does not accept integers

Step-by-Step Solution

Solution:

Step 1: Understand listOf()
listOf() creates an immutable list in Kotlin.
Step 2: Check add() method
add() is a mutating method and cannot be called on immutable lists.
Step 3: Evaluate other options
The add() method requires an index parameter is incorrect because add() can be called without index on mutable lists. The list must be declared with var instead of val is irrelevant since val or var does not affect mutability of the list itself. The listOf() function does not accept integers is false; listOf() accepts integers.
Final Answer:
listOf() creates an immutable list, so add() is not allowed -> Option C
Quick Check:
Immutable list cannot be modified [OK]

Quick Trick: listOf() returns immutable list; add() only works on mutable lists [OK]

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