/* Read a double value from fp. / double read_double (FILE fp) { double d; assert(fp != NULL); fscanf(fp, %lf, d); return d; }

The code above contains a common error. Which one of the following describes it?

Question

Multiple choice

fscanf() will fail to match floating-point numbers not preceded by whitespace.
The format specifier %lf indicates that the corresponding argument should be long double rather than double.
The format specifier %lf is recognized by fprintf() but not by fscanf().
D must be initialized prior to usage.

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Accepted Answer

The call to fscanf() requires a pointer as its last argument.

/* Read a double value from fp. */ double read_double (FILE * fp) { double d; assert(fp != NULL); fscanf(fp, %lf, d); return d; } The code above contains a common error. Which one of the following describes it?