method

%

v1_9_3_125 - Show latest stable - 1 note - Class: String

%(p1) public

Format—Uses str as a format specification, and returns the result of applying it to arg. If the format specification contains more than one substitution, then arg must be an Array or Hash containing the values to be substituted. See Kernel::sprintf for details of the format string.

"%05d" % 123                              #=> "00123"
"%-5s: %08x" % [ "ID", self.object_id ]   #=> "ID   : 200e14d6"
"foo = %{foo}" % { :foo => 'bar' }        #=> "foo = bar"

Show source

static VALUE
rb_str_format_m(VALUE str, VALUE arg)
{
    volatile VALUE tmp = rb_check_array_type(arg);

    if (!NIL_P(tmp)) {
        return rb_str_format(RARRAY_LENINT(tmp), RARRAY_PTR(tmp), str);
    }
    return rb_str_format(1, &arg, str);
}

October 3, 2009

1 thank

Use it with HAML

Like Henrik pointed out <a href=“http://henrik.nyh.se/2008/01/surround-helper-alternative-in-haml”>in his blogpost, this method is particulary useful when using HAML (http://haml-lang.com/) in Rails.

Instead of usind the HAML-Helper ‘surround’ (etc) you can just write

= "(%s)" % link_to("Edit", ...)

Or with two Arguments:

= "(%s, %s)" % ["Edit", "Delete"]

Thanks very much, Henrik!

%

Related methods

Use it with HAML