Tham khảo tài liệu 'the new c standard- p9', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | General 796 Coding Guidelines The visual similarity of these letters is discussed elsewhere. 792 character visual similarity 795 There is no specific limit on the maximum length of an identifier. Commentary The standard does specify a minimum limit on the number of characters a translator must consider as 282 internal significant Tninletnentations arc free to ionore characters once this limit is reached The ionored characters identifier s AgiiAAxcaxiA. are nee uo ignore cnaracters once aaaas aaaaaaa as reaciievi. ine Agnorevi- dataciets significant charac HrA nr it frvrm TYQT t r vf dTirrtlYAT tPilrATi Tt ic no if fliAxr Hirl nr it qtytyaqt in thA caiitpa nt dll ters. do not form part of another token. it is as if they did not appear in the source at all. 283 external identifier significant charac- C90 ters The C90 Standard does not explicitly state this fact. Other Languages Few languages place limits on the maximum length of an identifier that can appear in a source file. Like C some specify a lower limit on the number of characters that must be considered significant. Coding Guidelines Using a large number of characters in an identifier spelling has many potential benefits for instance it provides the opportunity to supply a lot of information to readers or to reduce dependencies on existing reader knowledge by spelling words in full rather than using abbreviations. There are also potential costs for instance they can cause visual layout problems in the source requiring new-lines within an expression in an attempt to keep the maximum line length within the bounds that can be viewed within a fixed-width window or increase the cognitive effort needed to visually scan source containing them. The length of an identifier is not itself directly a coding guideline issue. However length is indirectly inwr ilwArl in montr irlAMtifiat T nAT ni vrdhilitTr Arrnfncdhilitw dnrl ncdhilitw icciiAC whir ll dt A rlicAiiccArl a cAtuliAi A 792 identifier
