Some times we may need a float value 2.345 instead of complete float value 2.345768.
In such cases we need to trim the float value.The function below demonstrates how it can be done..

function name:                trimFloat( )
param1: float f;        the original float value , i.e., 2.345768
param2:int decimals; how many number of digits we want after the point (.)
return:                       It returns the trimmed float value

float trimFloat(float f, int decimals)
{
    char valueStr[20] = {NULL};
    sprintf(valueStr, "%f", f); 

    int i=0, d=0, sign=0;
    float val = 0.0f;
    float pow = 1.0f;

    int length = strlen(valueStr);
    if (length <= 0)
        return 0;

        //omit spaces if any
    for (i = 0; isspace(valueStr[i]); ++i)
        continue;

        //check weather flost value is negative or positive
    sign = (valueStr[i] == '-') ? -1 : 1;
    if (valueStr[i] == '-' || valueStr[i] == '+')
        ++i;

        //get the value and store it in val
    for (val = 0.0f; isdigit(valueStr[i]); ++i)
        val = 10.0f * val + valueStr[i] - '0';

        //if '.' is occur, just traverse it
    if (valueStr[i] == '.')
        ++i;
    
        //now "d<decimals" condition checkes how many digits you want after the point/dot/'.'
    for (pow = 1.0f, d=0; isdigit(valueStr[i]) && d<decimals; ++i, ++d)
    {
        val = 10.0f * val + valueStr[i] - '0';
        pow *= 10;
    }

        //return result
    return sign * val / pow;
}

The same function we can use for trimming double ( when we trimming double, then ‘val’ and ‘pow’ are double data types in the above program).

Note:
I have tested it on VS2003 and its giving exact values i.e., 2.34 / 2.345 / 2.3457 depending on ‘decimals’ variable. In VS2005, its giving 2.340000 / 2.345000 / 2.345700.