Arithmetic Problem
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When I try to perform the math below I get an answer of 0, but the result of the below should be 5.76 Int64 lpTotalNumberOfFreeBytes = 41085476864; Int64 lpTotalNumberOfBytes = 712212955136; Int64 strAnswer = ((lpTotalNumberOfFreeBytes / lpTotalNumberOfBytes) * 100); Does anyone see what I am doing wrong here? Thanks
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When I try to perform the math below I get an answer of 0, but the result of the below should be 5.76 Int64 lpTotalNumberOfFreeBytes = 41085476864; Int64 lpTotalNumberOfBytes = 712212955136; Int64 strAnswer = ((lpTotalNumberOfFreeBytes / lpTotalNumberOfBytes) * 100); Does anyone see what I am doing wrong here? Thanks
hi, int/int performs an integer division; you should consider one of these fixes: - use float or double everywhere - postpone division, hence do 100*int/int instead of int/int*100 (there is an increased risk of overflowing when doing all multiplies before all divides) The above holds true in most programming languages (C, C++, Java, C#, ...). :)
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When I try to perform the math below I get an answer of 0, but the result of the below should be 5.76 Int64 lpTotalNumberOfFreeBytes = 41085476864; Int64 lpTotalNumberOfBytes = 712212955136; Int64 strAnswer = ((lpTotalNumberOfFreeBytes / lpTotalNumberOfBytes) * 100); Does anyone see what I am doing wrong here? Thanks
You can use float everywhere as Luc adviced you. But if you for some reason need to store lpTotalNumberOfFreeBytes and lpTotalNumberOfBytes as Int64 you can covert their values in division expression like this:
((float)lpTotalNumberOfFreeBytes / (float)lpTotalNumberOfBytes )*100;However this expression return float value so you need to change type of strAnswer from Int64 to float or convert explicitly convert result to Int64:Int64 strAnswer = (Int64) (((float)lpTotalNumberOfFreeBytes / (float)lpTotalNumberOfBytes )*100);But remember if you convert float to Int64 system will cut off everything behind decimal point, so in this particular case result 5.7687068 will be converted to 5. hth