# if-then
## English
### Alternative forms

* if/then, if–then

### Noun

if-then (plural if-thens)
* A proposition or statement about what should or does occur when a certain condition is met.
** 2007, Nicholas Rescher, Conditionals, MIT Press, →ISBN, page 13:Disposition statements are always tantamount to conditional if-thens. (“Glass is fragile” amounts to “If glass is subjected to a shock, it will break”; “Wood is combustible” comes to “If wood is exposed to fire, it will burn”; and so on.)
** 2015, Gretchen Rubin, Better Than Before: What I Learned About Making and Breaking Habits—to Sleep More, Quit Sugar, Procrastinate Less, and Generally Build a Happier Life, Broadway Books, →ISBN:Over time, I created a list of some of my own if-thens: If I want to get a lot of original writing done, I go to the library, where I don’t have Internet. If offered wine, I decline.
** 2023, Alicia Britt Chole, The Night Is Normal: A Guide Through Spiritual Pain, Tyndale Refresh, →ISBN, page 106:Or maybe her if-then was shaped more like a question: Surely God would not have brought this child here if it was not His plan to keep her here, right? Our if-thens can be quite similar. If God really loves me, then He won’t let my heart be broken again. If God allows a door to open, then walking through it will bring me joy.
* (programming) A conditional statement; a line of code that specifies a Boolean condition to check and a statement to execute when that Boolean evaluates to true.
** 1981, Apple Orchard, page 31:List Formatter makes properly-spaced & indented listings with page breaks; each statement on new line, if-thens and loops called out; a great de-bugger!
** 1985, 1985 Symposium on Logic Programming: July 15-18, 1985; Sheraton Boston Hotel Boston, Mass., IEEE Computer Society Press, →ISBN, page 71:Storing (closed) predicate definitions in this form (if all the predicates are so stored, and there never were any cuts or if-thens in the first place, we have the well-known "completion" of a logic program) makes the coding of source-level tools simpler.
** 1989 December, David W. Long, Michael R. Wagner, “Insect Pest Management Expert Systems in Multiresource Management of Ponderosa Pine”, in Multiresource Management of Ponderosa Pine Forests: Nov. 14 - 16, 1989, Flagstaff, Arizona (General Technical Report RM-185), page 260:1. The problem is well bounded, 2. There are many empirical if/thens that lead to a correct solution, 3. The total number of if/thens is sufficient to bring you close to a right answer (Mazur 1987).
** 1992, Donald L. DeAngelis, Louis J. Gross, editors, Individual-Based Models and Approaches in Ecology: Populations, Communities and Ecosystems, Chapman and Hall, →ISBN, pages 154–155:Many if-thens will degrade vector performance below that of a scalar version that computes only the correct branch.
** 1994, Compute!, page 30:Think of this process as programming with pictures, complete with loops, pauses, if-thens, and so on.
** 2000, Harold J. Rood, Logic and Structured Design for Computer Programmers, Brooks/Cole, →ISBN, page ix:Finally, they use descriptions and statements from set theory to provide material for flowcharting problems that contain multiple decisions (nested if-thens).
** 2001, Mark Guzdial, Squeak: Object-Oriented Design with Multimedia Applications, Prentice Hall, →ISBN, page 35:Simple statements (like assignments and if-thens) are executed serially.
** 2004, Jim, quotee, “Co-Evolution of Design and Pedagogy Online”, in Sasha A. Barab, Rob Kling, James H. Gray, editors, Designing for Virtual Communities in the Service of Learning (Learning in Doing: Social, Cognitive and Computational Perspectives), Cambridge University Press, →ISBN, page 253:But I think that the badge system is very motivating, and if one of your goals is to get students to become more proficient in the programming, then this is certainly a way to do that. Because you set not a very high bar toward attaining these things and some of them I think are quite challenging – you know, doing the ones for lists, and the if-thens, and all that.
** 2004, Macworld, page 96:However, you can neither create multiple if-thens that execute simultaneously, nor create a rule based on a file’s Kind—so this utility’s utility is limited (November 2003).
** 2005 February, Make: Technology on Your Time, volume 01, O’Reilly Media, Inc., →ISBN, page 160:Have you noticed any similarities between “programming” a mechanical system and writing software? / The logical problems are absolutely the same. In the mechanical and in the computer, there are equivalents of variables and if-thens.
** 2012, Kim Stanley Robinson, 2312, Hachette, →ISBN:There’s some recursive programming in her that gives more weight to associative and metaphorical thinking than to logical if-thens.