End of Life Ruby 3.1 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

instance method

String#to_f

to_f → float

static VALUE
rb_str_to_f(VALUE str)
{
    return DBL2NUM(rb_str_to_dbl(str, FALSE));
}

Returns the result of interpreting leading characters in self as a Float:

Example

'3.14159'.to_f  # => 3.14159
'1.234e-2'.to_f # => 0.01234

Characters past a leading valid number (in the given base) are ignored:

Example

'3.14 (pi to two places)'.to_f # => 3.14

Returns zero if there is no leading valid number:

Example

'abcdef'.to_f # => 0.0

See also #toeuc #to_i #to_d #tojis also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.0