Quick Answer

Compiler cannot find a declared symbol

Understanding the Issue

This error occurs when the compiler encounters an identifier (function, variable, class) that hasn't been declared or isn't in scope. Common causes include typos, missing imports, or visibility issues.

The Problem

This code demonstrates the issue:

Kotlin Error 
// Problem: Undeclared variable
print(undeclaredVar)

The Solution

Here's the corrected code:

Kotlin Fixed 
// Solution 1: Declare the variable
val declaredVar = "Hello"
print(declaredVar)

// Solution 2: Check imports
import java.util.Date
print(Date()) // Now resolved

// Solution 3: Check scope
fun main() {
    val visible = "In scope"
    print(visible)
}

Key Takeaways

Verify spelling, imports, and scope when encountering unresolved references.