The memoir class - The UK TeX Archive

18.16. Checking the processor\checkarrayindex checks if 〈arrayname〉 is an array and if 〈index〉 is a valid index for thearray. If both conditions hold then \ifbounderror is set false, but if either 〈arrayname〉is not an array or, if it is, 〈index〉 is out of range then \ifbounderror is set true.\stringtoarray{〈arrayname〉}{〈string〉}\arraytostring{〈arrayname〉}{〈result〉}The macro \stringtoarray puts each character from 〈string〉 sequentially into the〈arrayname〉 array, starting at index 1. The macro \arraytostring assumes that〈arrayname〉 is an array of characters, and defines the macro 〈result〉 to be that sequenceof characters. For example:\stringtoarray{MyArray}{Chars}\arraytostring{MyArray}{\MyString}is equivalent to\def\MyString{Chars}\checkifinteger{〈num〉}\ifintegerThe command \checkifinteger ckecks if 〈num〉 is an integer (not less than zero). If it isthen \ifinteger is set true, otherwise it is set false.Note.Please note that \checkifinteger may only work on simple input.18.16 CHECKING THE PROCESSOR18.16.1 Checking for pdfLaTeXBoth LaTeX and pdfLaTeX can be run on the same document. LaTeX produces a .dvi fileas output, while pdfLaTeX can produce either a .dvi or a .pdf file. On modern systemspdfLaTeX produces a pdf file by default.If you want a dvi file output use LaTeX and if you want a pdf file use pdfLaTeX.\ifpdf ... \fiThe class provides \ifpdf which is true when the document is being processed by pdfLa-TeX and false otherwise. You can use it like this:\ifpdfcode for pdfLaTeX only\elsecode for LaTeX only\fiIf there is no LaTeX specific code then don’t write the \else part.337