conversion from int to char

Hi,

I am trying to write to a binary file and while I am setting the values I have to convert an int to a char using
rec.cStopReason = (char) m_nStopCode; where the defnitions are as follows.
char cStopReason; //25
int m_nStopCode;

For all the values in m_nstopcode it works fine but when I have the value as 128 in m_nstopcode I get cStopReason as -128.

Can anyone help me understand why it is doing that.

Thanks,
Pushpa.

its because you are using a signed char. If you will not have negative values, unsigned char is better and have twice the positive range of a signed char.

On most computers, a char can only range from -128 to 127.

Code:

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rec.cStopReason = (unsigned char) m_nStopCode;

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Quote:

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Originally Posted by Skizmo

Code:

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rec.cStopReason = (unsigned char) m_nStopCode;

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You think this will work?:

Code:

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char cStopReason;
int m_nStopCode = 128;

cStopReason = (unsigned char) m_nStopCode;

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cStopReason is still a signed char, hence it cannot handle the value of 128 and will wrap over to -128!

To make this work you'll need to declare cStopReason as unsigned char;

Code:

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unsigned char cStopReason; //25
int m_nStopCode = 128;

cStopReason = (unsigned char) m_nStopCode;

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Best regards,

Laitinen