method

start_with?

v1_8_7_72 - Show latest stable - 2 notes - Class: String

start_with?(...) public

Returns true if str starts with the prefix given.

/*
 *  call-seq:
 *     str.start_with?([prefix]+)   => true or false
 *  
 *  Returns true if <i>str</i> starts with the prefix given.
 */

static VALUE
rb_str_start_with(argc, argv, str)
    int argc;
    VALUE *argv;
    VALUE str;
{
    int i;
    VALUE pat;

    for (i=0; i<argc; i++) {
        VALUE prefix = rb_check_string_type(argv[i]);
        if (NIL_P(prefix)) continue;
        if (RSTRING(str)->len < RSTRING(prefix)->len) continue;
        pat = get_arg_pat(prefix);
        if (rb_reg_search(pat, str, 0, 1) >= 0)
            return Qtrue;
    }
    return Qfalse;
}

May 3, 2012

0 thanks

Starts with a Capital Letter

(or any regular expression you’d like)

'Abracadabra'[0..0] =~ /[A-Z]/       # => true

May 17, 2012

0 thanks

Starts with capital letter alternative

Just adding an anchor to the regular expression seems simpler (and was faster in my benchmarks, not that that matters much):

'Abracadabra' =~ /^[A-Z]/

start_with?

Related methods

Starts with a Capital Letter

Starts with capital letter alternative