This chapter has described the nuts and bolts of the JavaScript language. The native language contains considerable detail without any reference to other technologies such as Web browsers. With data types, expressions, statements and functions a script could achieve a great deal, if only it wasn't hampered by a lack of facilities for doing input and output. The powerful concept of objects presents an opportunity to collect data and code together in a way that can be quite compact and flexible, especially in the way that object can track other objects via their own properties.
The Reference Section contains more specific information about the language. In the next chapter, we will see how a JavaScript interpreter combined with a Web browser or other host program removes the input/output problem and creates many opportunities for scripts to be usefully executed.