. ge :: MarkI Timesharing :: 711224B BASICLanguageReferenceManual Nov1970 . e, the BACKSPACE statement causes the data pointer to bestepped backward to the beginning of the current line. Files being printed or written cannot bebackspaced and then written to, because backspacing places the file in the read mode. The formof the statement is BACKSPACE #1 file designator You can use this statement to backspace to a particular data item or to the beginning of a may be used with ASCII files only. Example: If the file DATA contains 10 1,2,8,4,5,6,7,8 20 #,10,11,12,18,14,15,16 then in the prog
. ge :: MarkI Timesharing :: 711224B BASICLanguageReferenceManual Nov1970 . e, the BACKSPACE statement causes the data pointer to bestepped backward to the beginning of the current line. Files being printed or written cannot bebackspaced and then written to, because backspacing places the file in the read mode. The formof the statement is BACKSPACE #1 file designator You can use this statement to backspace to a particular data item or to the beginning of a may be used with ASCII files only. Example: If the file DATA contains 10 1,2,8,4,5,6,7,8 20 #,10,11,12,18,14,15,16 then in the program 4oi^iiy5#,i,E,f,GvH , ? - ,;, ; \ Line 20 will read the values 1, 2, 3, and 4 into variables A, B, C, and D, and the data pointerwill be advanced to the next item, 5. Line 30 will then backspace the data pointer to the pre-vious item, the number 4. Line 40 will then assign values of 4, 5, 6, and 7 to variables E, F,G, andH. It is possible to backspace past the beginning of a file. When this happens, the first line in thefile is used again and again. Example:. 82 In the preceding example, after Line 20 the data pointer is positioned to indicate 16, the nextitem in the file. The loop in lines 30 to 50 backspaces 16 times, moving the data pointer pastthe beginning of the file. This causes the data pointer to begin backspacing from the end of thefirst line of data. In this case, the pointer will indicate 8, and line 60 assigns the values 8, 9,and 10 to R, S, and T. If the backspace loop had been greater, the first line of data in the filewould have been repeatedly backspaced over, and the data pointer would have been positioned atsome item in the first line. The following example illustrates backspacing of a file in the input : iO IILIS DAm 30 BACKSPACE #1 SO PKINT ^TmST SKT VALUES^60 FRIOT A;B,C;B;E;F;0;H?0 3PBINT* 80 FRIOT ^*SSC0HD SET 0F YAhVEB90 wmm I>rjK^L;M;M;0;PEM) FIBST SET <2(f YAL0KS101 2 3 4 § # ? 8 Sm0iD SET 0F VALUES101 2 3 4 5 e 7 8 Note
Size: 2918px × 856px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidbitsaversgem, bookyear1919
