In this chapter, we have learned about the different types of variables and their declarations. We also discussed type inference and how Kotlin helps to improve productivity by allowing a programmer to ignore explicit type declarations. This chapter has explained null safety and how Kotlin helps us to write safe and concise code. We have also discussed if statements, else as an expression, loops, labeled for loops, continue, and break statements in detail. This chapter concluded by discussing functions and their important features, including functions as an expression, named parameters, and package-level functions.