Q32100: RANDOMIZE Results Differ in QB.EXE Versus Compiled .EXE
Article: Q32100 Product(s): See article Version(s): 4.00 4.00b 4.50 Operating System(s): MS-DOS Keyword(s): ENDUSER | buglist4.00 buglist4.00b fixlist4.50 B_BasicCom | mspl13_basic Last Modified: 8-DEC-1989 The RANDOMIZE statement gives different results inside the QuickBASIC (QB.EXE) environment from the results it gives in an executable file (.EXE) using the same seed. This difference poses a problem for software developers using the QB.EXE environment who depend upon a given seed for the RANDOMIZE statement to make the RND function return the same series of random numbers as a compiled .EXE program. Microsoft has confirmed this to be a problem in QuickBASIC Versions 4.00 and 4.00b, and in the Microsoft BASIC Compiler Version 6.00 for MS-DOS and MS OS/2 (buglist6.00). This problem has been corrected in QuickBASIC Version 4.50 and in the Microsoft BASIC Compiler Version 7.00 (fixlist7.00). This problem does not occur in QuickBASIC Version 3.00; the results obtained from within the QuickBASIC Version 3.00 environment and the results from the executable program are the same. Note: The differing random-number series using the same seed between QuickBASIC Version 3.00 and Version 4.00 is expected and is not considered to be a problem. When a program is executed several times (with the same seed for the RANDOMIZE statement) from a given environment, the RND function returns the same number series every time (in all versions of Microsoft BASIC), which is expected behavior. The following code demonstrates the problem: RANDOMIZE 1000 FOR i = 1 TO 10 PRINT INT(RND * 10) + 1 NEXT i END The following are the results (every time) when executed from inside the QuickBASIC Version 4.00b QB.EXE editor: 7 2 4 3 2 5 1 5 4 7 The following are the results (every time) when executed from the .EXE file created by QuickBASIC Version 4.00b: 8 5 7 6 2 10 3 4 7 8 The following are the results (every time) when executed from QuickBASIC Version 3.00 or an executable file compiled in Version 3.00: 10 7 10 4 3 4 10 1 3 4
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