C / C++ / MFC

Andy202 wrote:

Could I get the floating value by doing this:-

union<br />
{<br />
float data;<br />
unsigned short buff[2];<br />
}convert;<br />
<br />
convert.buff[0] = message[2];<br />
convert.buff[1] = message[3];<br />
<br />
float val = convert.data;

unsigned short w1 = 0xc3f5;    // The float is 3.14<br />
unsigned short w2 = 0x4840;<br />
union<br />
{<br />
	float data;<br />
	unsigned short buff[2];<br />
	BYTE floating[4];<br />
}convert;<br />
<br />
convert.floating[0] = (BYTE)(w1/256);		// This gives val = 3.1400001<br />
convert.floating[1] = (BYTE)(w1 & 0x00FF);<br />
convert.floating[2] = (BYTE)(w2/256);<br />
convert.floating[3] = (BYTE)(w2 & 0x00FF);<br />
<br />
//convert.buff[1] = w1;				// This gives val = -490.56445<br />
//convert.buff[0] = w2;<br />
<br />
float val = convert.data;

convert.buff[0] = message[2];
convert.buff[1] = message[3];

convert.buff[<code>1</code>] = message[2];
convert.buff[<code>0</code>] = message[3];

Andy202 wrote:

I receive a 20 word message and two words of this message define a floating value;

unsigned short message [20]; // Message buffer

e.g. message [2] and message[3] define a float with the mantissa in the lower byte of message[3].

Could I get the floating value by doing this:-

union
{
  float data;
  unsigned short buff[2];
}convert;

convert.buff[0] = message[2];
convert.buff[1] = message[3];

float val = convert.data;

Or what is the best way to get this 32 bit embedded floating point value.

Andy

float result = *(reinterpret_cast<float *>(message + 2);

VonHagNDaz wrote:

so chHold == "0"

would be differnt than

chHold = 0

led mike wrote:

0 == myvariable;

VonHagNDaz wrote:

char* chHold;
strHold.copy(chHold, strHold.length());

VonHagNDaz wrote:

I know that atoi() will return a 0 if the value of chHold = "This is not an int," So my question is : what is a good way to check if the zero is actually the number 0 and not a returned zero as the result of atoi("This is not an int").