instance method

Integer#floor

(?::int digits) -> ::Integer

floor(ndigits = 0) → integer

static VALUE
int_floor(int argc, VALUE* argv, VALUE num)
{
    int ndigits;

    if (!rb_check_arity(argc, 0, 1)) return num;
    ndigits = NUM2INT(argv[0]);
    if (ndigits >= 0) {
        return num;
    }
    return rb_int_floor(num, ndigits);
}

Returns an integer that is a “floor” value for self, as specified by the given ndigits, which must be an integer-convertible object.

When self is zero, returns zero (regardless of the value of ndigits):

Example
```
0.floor(2)  # => 0
0.floor(-2) # => 0
```
When self is non-zero and ndigits is non-negative, returns self:

Example
```
555.floor     # => 555
555.floor(50) # => 555
```
When self is non-zero and ndigits is negative, returns a value based on a computed granularity:
- The granularity is 10 ** ndigits.abs.
- The returned value is the largest multiple of the granularity that is less than or equal to self.
Examples with positive self:

ndigits Granularity 1234.floor(ndigits)

-1 10 1230

-2 100 1200

-3 1000 1000

-4 10000 0

-5 100000 0

Examples with negative self:

ndigits Granularity -1234.floor(ndigits)

-1 10 -1240

-2 100 -1300

-3 1000 -2000

-4 10000 -10000

-5 100000 -100000

ndigits	Granularity	1234.floor(ndigits)
-1	10	1230
-2	100	1200
-3	1000	1000
-4	10000	0
-5	100000	0

ndigits	Granularity	-1234.floor(ndigits)
-1	10	-1240
-2	100	-1300
-3	1000	-2000
-4	10000	-10000
-5	100000	-100000

Related: Integer#ceil.

See also #fdiv #gcd #even? #gcdlcm also in 4.1 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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