{VERSION 3 0 "IBM INTEL NT" "3.0" } {USTYLETAB {CSTYLE "Maple Input" -1 0 "Courier" 0 1 255 0 0 1 0 1 0 0 1 0 0 0 0 }{CSTYLE "2D Math" -1 2 "Times" 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 }{CSTYLE "Hyperlink" -1 17 "" 0 1 0 128 128 1 0 0 1 0 0 0 0 0 0 } {CSTYLE "2D Output" 2 20 "" 0 1 0 0 255 1 0 0 0 0 0 0 0 0 0 }{CSTYLE " " 0 21 "" 0 1 0 0 0 1 0 0 0 0 2 0 0 0 0 }{CSTYLE "Help Heading" -1 26 "" 1 14 0 0 0 0 0 1 0 0 0 0 0 0 0 }{PSTYLE "Normal" -1 0 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }0 0 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Heading 1" 0 3 1 {CSTYLE "" -1 -1 "" 1 18 0 0 0 0 0 1 0 0 0 0 0 0 0 }1 0 0 0 6 6 0 0 0 0 0 0 -1 0 }{PSTYLE "Maple Output" 0 11 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }3 3 0 -1 -1 -1 0 0 0 0 0 0 -1 0 }{PSTYLE "Bullet Item" 0 15 1 {CSTYLE "" -1 -1 "" 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 }0 0 0 -1 3 3 0 0 0 0 0 0 15 2 }} {SECT 0 {SECT 0 {PARA 0 "" 0 "" {TEXT 26 7 "Advice:" }{TEXT -1 36 " Th e differences between cat and dot" }}{PARA 0 "" 0 "" {TEXT -1 0 "" }} {PARA 0 "" 0 "" {TEXT -1 58 "There are two ways to join two strings to gether: with the " }{MPLTEXT 0 21 3 "cat" }{TEXT -1 16 " function (e.g . " }{MPLTEXT 0 21 8 "cat(a,b)" }{TEXT -1 34 ") and with the dot opera tor (e.g. " }{MPLTEXT 0 21 3 "a.b" }{TEXT -1 83 "). In many situation s these have identical results, but there are two differences:" }} {PARA 15 "" 0 "" {TEXT -1 192 "The dot operator does not evaluate its \+ first argument. The other arguments are evaluated. The cat function, on the other hand, evaluates all its arguments. In the example below , evaluating " }{MPLTEXT 0 21 1 "a" }{TEXT -1 12 " results in " } {MPLTEXT 0 21 1 "c" }{TEXT -1 13 ". The first " }{MPLTEXT 0 21 1 "a" }{TEXT -1 4 " in " }{MPLTEXT 0 21 5 "a.a.a" }{TEXT -1 37 " is not eval uated, but all the other " }{MPLTEXT 0 21 1 "a" }{TEXT -1 7 "'s are." }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 13 "a:= b: b:= c:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 6 "a.a.a;" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#%$accG" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 11 "cat(a,a,a); " }}{PARA 11 "" 1 "" {XPPMATH 20 "6#%$cccG" }}}{PARA 15 "" 0 "" {TEXT -1 65 "The result of the dot operator is evaluated, while the result o f " }{MPLTEXT 0 21 3 "cat" }{TEXT -1 53 " is not evaluated. In the ex ample below, evaluating " }{MPLTEXT 0 21 2 "cd" }{TEXT -1 12 " results in " }{MPLTEXT 0 21 2 "ef" }{TEXT -1 39 ". Recalling the unevaluated result of " }{MPLTEXT 0 21 3 "cat" }{TEXT -1 6 " with " }{MPLTEXT 0 21 1 "%" }{TEXT -1 14 " evaluates it." }}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 8 "cd:= ef:" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 4 " c.d;" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#%#efG" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 9 "cat(c,d);" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#%#cd G" }}}{EXCHG {PARA 0 "> " 0 "" {MPLTEXT 1 0 2 "%;" }}{PARA 11 "" 1 "" {XPPMATH 20 "6#%#efG" }}}}{SECT 0 {PARA 3 "" 0 "" {TEXT 26 9 "See also :" }}{PARA 0 "" 0 "" {HYPERLNK 17 "cat" 2 "cat" "" }{TEXT -1 2 ", " } {HYPERLNK 17 "dot operator" 2 "dot" "" }{TEXT -1 2 ", " }{HYPERLNK 17 "eval" 2 "eval" "" }}}{SECT 0 {PARA 0 "" 0 "" {TEXT 26 24 "Maple Advis or Database, " }{TEXT -1 15 " R. Israel 1998" }}}}{MARK "3" 0 } {VIEWOPTS 1 1 0 1 1 1803 }