float to CString conversion not exact

[YouPoP]

For a reason i don't know, if i convert a float to a cstring, it does not convert to an exact value for all values except round numbers or 1/2 numbers;

the following code (used to convert and later show as text in a MFC Document)

char buffer1[_CVTBUFSIZE];
_gcvt(i_A11, 12, buffer1);
CString SA11 = (CString) buffer1;
 

output
float i_A11 = 1,2 and once converted to Cstring SA11 = "1.20000004768"
float i_A11 = 1,0 and once converted to Cstring SA11 = "1."
float i_A11 = 1,5 and once converted to Cstring SA11 = "1.5"

thanks in advance for the help!

[JosAH]

Read What every computer scientist should know about floating-point arithmetic.

kind regards,

Jos