In this chapter, you learned how to work basic objects by demonstrating the use of built-in functions. They are the vocabulary of R in practice. You learned some basic functions to test and get object types and to access and reshape data dimensions. You learned about a number of logical operators and functions to filter data.

To work with numeric data structures, you learned basic math functions, built-in numeric methods to find roots and do calculus, and some statistical functions to perform random sampling and make summaries of data. You also understood the apply-family functions that make it easier to iterate and collect results.

Another important category of data is string, which is represented by character vectors. In the next chapter, you will learn string-manipulation techniques to facilitate text analysis.