# Constant arrays - Thread: https://externals.io/message/56949 - Original archive: https://news-web.php.net/php.internals/56949 - Started by Barbu Paul Gh. on 2011-12-19T20:20:09+00:00 - Messages: 10 - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #56949 — Barbu Paul Gh. — 2011-12-19T20:20:09+00:00 URL: https://externals.io/message/56949#56949 Hello! I wonder why I cannot assign arrays to constants. According to the PHP manual: "only scalar and null values are allowed. Scalar values are integer, float, string or boolean values." What is the mechanism behind this? What's the explanation? -- Common sense is not so common - Voltaire http://tweak-it.tk/ - Personal portfolio and web-log - Barbu Paul - Gh. Visit My GitHub profile to see my open-source projects - https://github.com/paullik --- ## #56950 — Paul Dragoonis — 2011-12-19T20:23:59+00:00 URL: https://externals.io/message/56949#56950 · In reply to: #56949 Barbu, This is how constants work in all viable languages such as C/++. They are not 'variables of data', they contain scalar values so that you can have a maintainable source for your value to refer to later. http://msdn.microsoft.com/en-us/library/357syhfh(v=vs.80).aspx I believe constants come from the philosophy of 'enums' in C. Just google some more on it. Regards, - Paul. > Hello! > > I wonder why I cannot assign arrays to constants. > According to the PHP manual: > "only scalar and null values are allowed. Scalar values are integer, float, > string or boolean values." > > What is the mechanism behind this? > What's the explanation? > > -- > > Common sense is not so common - Voltaire > http://tweak-it.tk/ - Personal portfolio and web-log - Barbu Paul - Gh. > Visit My GitHub profile to see my open-source projects - > https://github.com/paullik --- ## #56951 — keisial@gmail.com — 2011-12-19T20:47:43+00:00 URL: https://externals.io/message/56949#56951 · In reply to: #56950 > Barbu, > > This is how constants work in all viable languages such as C/++. I disagree. In C you can have: const data foo[] = { { "Data1", 2 }, { "Data2", 78 } }; It's not unusual in php to have a complex structure that won't change in a variable. It should be an array, but as array is not allowed as content, you need to leave it as a static variable that you won't never change. --- ## #56952 — Paul Dragoonis — 2011-12-19T20:50:31+00:00 URL: https://externals.io/message/56949#56952 · In reply to: #56951 2011/12/19 Ángel González : > > > […] > I disagree. In C you can have: > const data foo[] = { { "Data1", 2 }, { "Data2", 78 } }; Agreed, i was more thinking of #define (not const), when setting up values such as 'MAX_LEN', being a typical use case for PHP. > > It's not unusual in php to have a complex structure that won't change > in a variable. It should be an array, but as array is not allowed as > content, > you need to leave it as a static variable that you won't never change. --- ## #56957 — Qiang Guo — 2011-12-20T00:28:51+00:00 URL: https://externals.io/message/56949#56957 · In reply to: #56949 Yes, I am wondering too. For mechanism you can refer to the source code, and can someone explain why we cannot have constant arrays ? Qiang --- ## #56955 — Daniel Convissor — 2011-12-20T00:43:51+00:00 URL: https://externals.io/message/56949#56955 · In reply to: #56949 Hi Barbu: > I wonder why I cannot assign arrays to constants. Do keep in mind that you can `serialize()` the array before storing it in a constant. Then use unserialize(CONSTANT) when you need the data. --Dan -- T H E A N A L Y S I S A N D S O L U T I O N S C O M P A N Y data intensive web and database programming http://www.AnalysisAndSolutions.com/ 4015 7th Ave #4, Brooklyn NY 11232 v: 718-854-0335 f: 718-854-0409 --- ## #56956 — Tom Boutell — 2011-12-20T01:02:28+00:00 URL: https://externals.io/message/56949#56956 · In reply to: #56955 This must be some strange definition of "constant" I do not understand, then (: On Mon, Dec 19, 2011 at 7:43 PM, Daniel Convissor wrote: > Hi Barbu: > > > […] > > Do keep in mind that you can `serialize()` the array before storing it in > a constant.  Then use unserialize(CONSTANT) when you need the data. > > --Dan > > -- >  T H E   A N A L Y S I S   A N D   S O L U T I O N S   C O M P A N Y >            data intensive web and database programming >                http://www.AnalysisAndSolutions.com/ >  4015 7th Ave #4, Brooklyn NY 11232  v: 718-854-0335 f: 718-854-0409 > > -- > > > -- Tom Boutell P'unk Avenue 215 755 1330 punkave.com window.punkave.com --- ## #56966 — jpauli — 2011-12-20T16:37:46+00:00 URL: https://externals.io/message/56949#56966 · In reply to: #56957 I guess constant array would mean that all the variables inside the array dimensions should not change. Just saying that, is a nonsense. If a constant could be an array, then that array could not contain variables, if not it wouldn't be constant any more as a change to one variable inside it would change its own meaning value. Julien.P > > Yes, I am wondering too. For mechanism you can refer to the source code, > and can someone explain why we cannot have constant arrays ? > > Qiang --- ## #56968 — David Muir — 2011-12-20T22:43:36+00:00 URL: https://externals.io/message/56949#56968 · In reply to: #56966 > I guess constant array would mean that all the variables inside the array > dimensions should not change. > Just saying that, is a nonsense. > > If a constant could be an array, then that array could not contain > variables, if not it wouldn't be constant any more as a change to one > variable inside it would change its own meaning value. > > Julien.P > > A constant can only contain static values. There was no mention of variables. Isn't a "constant" array basically the same as an Enum? David --- ## #56976 — jpauli — 2011-12-21T09:01:57+00:00 URL: https://externals.io/message/56949#56976 · In reply to: #56968 Okay, but those effectively don't exist in PHP ;) Julien > > > […] > > A constant can only contain static values. There was no mention of > variables. > > Isn't a "constant" array basically the same as an Enum? > > David