How can I check if a string can be converted to a float?

Question

First my context is that of a compiler writer who needs to convert floating point literals (strings) into float/double values. I haven\'t done any floating point programming

Answer 1

In C89 you may use sscanf.

For example:

float myfloat;

if(sscanf(str, "%f", &myfloat) != 1)
    /* String could not be converted */
else
    /* String was converted, myfloat is usable */