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instance method
BigDecimal#n_significant_digits
n_significant_digits → integer
ext/bigdecimal/bigdecimal.c
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static VALUE
BigDecimal_n_significant_digits(VALUE self)
{
ENTER(1);
Real *p;
GUARD_OBJ(p, GetVpValue(self, 1));
if (VpIsZero(p) || !VpIsDef(p)) {
return INT2FIX(0);
}
ssize_t n = p->Prec; /* The length of frac without trailing zeros. */
for (n = p->Prec; n > 0 && p->frac[n-1] == 0; --n);
if (n == 0) return INT2FIX(0);
DECDIG x;
int nlz = BASE_FIG;
for (x = p->frac[0]; x > 0; x /= 10) --nlz;
int ntz = 0;
for (x = p->frac[n-1]; x > 0 && x % 10 == 0; x /= 10) ++ntz;
ssize_t n_significant_digits = BASE_FIG*n - nlz - ntz;
return SSIZET2NUM(n_significant_digits);
}
Returns the number of decimal significant digits in self.
Example
BigDecimal("0").n_significant_digits # => 0 BigDecimal("1").n_significant_digits # => 1 BigDecimal("1.1").n_significant_digits # => 2 BigDecimal("3.1415").n_significant_digits # => 5 BigDecimal("-1e20").n_significant_digits # => 1 BigDecimal("1e-20").n_significant_digits # => 1 BigDecimal("Infinity").n_significant_digits # => 0 BigDecimal("-Infinity").n_significant_digits # => 0 BigDecimal("NaN").n_significant_digits # => 0