I call it my billion-dollar mistake. It was the invention of the null reference in 1965.

I was eventually persuaded of the need to design programming notations so as to maximize the number of errors which cannot be made, or if made, can be reliably detected at compile time.

You cannot teach beginners top-down programming, because they don't know which end is up.

Programmers are always surrounded by complexity; we cannot avoid it.... If our basic tool, the language in which we design and code our programs, is also complicated, the language itself becomes part of the problem rather than part of its solution.

I call it my billion-dollar mistake. It was the invention of the null reference in 1965.

In the development of the understanding of complex phenomena, the most powerful tool available to the human intellect is abstraction. Abstraction arises from the recognition of similarities between certain objects, situations, or processes in the real world and the decision to concentrate on these similarities and to ignore, for the time being, their differences.

Premature optimization is the root of all evil in programming.