In real-world applications, variables often refer to objects whose exact type is known only at runtime. Type checking allows programs to safely identify an object’s actual type before using it. Kotlin goes a step further by introducing smart casts , which automatically handle casting after a successful type check. This reduces boilerplate code and prevents common runtime errors. Table of Contents What Is Type Checking? Type Checking in Java Type Checking in Kotlin Smart Casts in Kotlin Java and Kotlin Comparison Interview Questions Conclusion 1. What Is Type Checking? Type checking is the process of verifying an object’s actual runtime type before performing operations specific to that type. This is commonly required when: A variable is declared as a parent type (e.g., Object or Any ) Objects come from external libraries or APIs Working with inheritance or polymorphism Without proper type checking, programs may crash with Clas...