Javascript incorporates some of the best and worst ideas in programming languages. In this segment, Doug Crockford introduces the Javascript programming language, covering all of the core language features, including numbers, strings, operators, arrays, objects, and functions, pointing out the good, the bad, and the ugly features of the language as he goes. You'll learn about some common Javascript patterns, why lambda is cool, why you should never, ever use eval, and why you should always declare everything.