Dijkstra, Edsger

Edsger Dijkstra, in full Edsger Wybe Dijkstra, (born May 11, 1930, Rotterdam, Netherlands—died August 6, 2002, Nuenen), Dutch computer scientist who developed the paradigm of structured programming for writing computer programs.

Dijkstra received a Ph.D. from the University of Amsterdam in 1959 while working at Amsterdam’s Mathematical Center (1952–62). He taught at the Technical University of Eindhoven from 1963 to 1973. He was a research fellow at the Burroughs Corporation from 1973 to 1984 and a professor of computer science at the University of Texas at Austin from 1984 to 2000.

Dijkstra was widely known for his 1959 solution to the graph-theory problem of the shortest path between two nodes of a network, which he devised in 20 minutes while sitting in a café with his fiancée, Maria Debets; the Dijkstra algorithm is still used to determine the fastest way between two points, as in the routing of communication networks and in flight planning. In 1960 he and Dutch computer scientist Jaap A. Zonnefeld developed the first compiler for the ALGOL-60 programming language. His research on the idea of mutual exclusion in communications led him to suggest in 1968 the concept of computer semaphores, which are used in concurrent programming in virtually every modern operating system.

Dijkstra’s letter “Go To Statement Considered Harmful” (1968) was extremely influential in the development of structured programming (which some called “gotoless programming”). In the letter he noted that the use of “go to” instead of statements such as “if then” led to sloppy programming in which the process as written in the program diverged from the process as it was actually executed. He instead championed a rigorous approach in which programs were built out of modular units with clear, single entrance and exit points. He received the Turing Award in 1972.