| .DEFtype Statement Details. |
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| DEFtype Statement Details |
|
| Syntax |
| DEFINT letterrange [,letterrange]... |
| DEFSNG letterrange [,letterrange]... |
| DEFDBL letterrange [,letterrange]... |
| DEFLNG letterrange [,letterrange]... |
| DEFSTR letterrange [,letterrange]... |
| |
| The letterrange has the form: |
| |
| letter1[-letter2] |
| |
| where letter1 and letter2 are any of the uppercase or lowercase |
| letters of the alphabet. Names beginning with the letters in |
| letterrange have the type specified by the last three letters of the |
| statement: integer (INT), long integer (LNG), single precision (SNG), |
| double precision (DBL), or string (STR). For example, in the following |
| program fragment, Message is a string variable: |
| |
| DEFSTR A-Q |
| . |
| . |
| . |
| Message="Out of stack space." |
| |
| The case of the letters in letterrange is not significant. |
| All of the following statements are equivalent: |
| |
| DEFINT I-N |
| DEFINT i-n |
| DEFINT i-N |
| |
| A type-declaration character (%, &, !, #, or $) always takes precedence |
| over a DEFtype statement. DEFtype statements do not affect record |
| elements. |
| |
| Note: I!, I#, I&, I$, and I% are all distinct variables, and each |
| may hold a different value. |
| |
| Differences from BASICA |
| |
| BASICA handles DEFtype statements differently. BASICA scans a |
| statement each time before executing it. If the statement contains a |
| variable without an explicit type (indicated by !, #, &, $, or %), |
| the interpreter uses the current default type. |
| |
| In the example below, when BASICA interprets line 20, it determines |
| that the current default type for variables beginning with I is |
| integer. Line 30 changes the default type to single precision. |
| When BASICA loops back to line 20, it rescans the line and uses |
| IFLAG as a single-precision variable. |
| |
| 10 DEFINT I |
| 20 PRINT IFLAG |
| 30 DEFSNG I |
| 40 GOTO 20 |
| |
| In contrast, QuickBASIC scans the text only once; once a variable |
| appears in a program line, its type cannot be changed. |
| |
