VB6 and .NET integer division
Description
In VBUC versions lower than 8.2, the division between two integers is migrated to a non-equivalent statement.
Consider the following VB6 code:
VB6 Code
Dim nLineCnt As Long
Dim nSplit As Long
Dim nItems As Long
'more code'
nItems = CLng(nLineCnt / nSplit)
The code was migrated to this:
.NET Code
int nLineCnt = 0;
int nSplit = 0;
int nItems = 0;
//more code
nItems = nLineCnt / nSplit;
That division statement is not equivalent in .NET because, for operands of integer type, the / operator returns an integer, consisting of the quotient rounded towards zero.
Consider the following examples:
VB6 Code
Dim nLineCnt As Long
Dim nSplit As Long
Dim nItems As Long
'more code'
nLineCnt = 13
nSplit = 5
nItems = CLng(nLineCnt / nSplit) 'nItems is 3'
The result in VB6 is 3.
.NET Code
int nLineCnt = 13;
int nSplit = 5;
int nItems = 0;
//more code
nItems = nLineCnt / nSplit; //nItems is 2
The result in .NET is 2.
To obtain a floating-point quotient, one of the operands should be cast as float, double, or decimal type:
.NET Code
int nLineCnt = 13;
int nSplit = 5;
int nItems = 0;
//more code
nItems = Convert.ToInt32((double)nLineCnt / nSplit); //nItems is 3
The result with the modifications is 3.
The code is now equivalent. Notice the result should be converted to an integer.
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