capitalize! ()
public
Modifies str by converting the first character to uppercase and
the remainder to lowercase. Returns nil if no changes are made. Note: case
conversion is effective only in ASCII region.
a = " hello "
a . capitalize! a
a . capitalize! Show source static VALUE
rb_str_capitalize_bang(VALUE str)
{
rb_encoding *enc;
char *s, *send;
int modify = 0;
unsigned int c;
int n;
str_modify_keep_cr(str);
enc = STR_ENC_GET(str);
rb_str_check_dummy_enc(enc);
if (RSTRING_LEN(str) == 0 || !RSTRING_PTR(str)) return Qnil;
s = RSTRING_PTR(str); send = RSTRING_END(str);
c = rb_enc_codepoint_len(s, send, &n, enc);
if (rb_enc_islower(c, enc)) {
rb_enc_mbcput(rb_enc_toupper(c, enc), s, enc);
modify = 1;
}
s += n;
while (s < send) {
c = rb_enc_codepoint_len(s, send, &n, enc);
if (rb_enc_isupper(c, enc)) {
rb_enc_mbcput(rb_enc_tolower(c, enc), s, enc);
modify = 1;
}
s += n;
}
if (modify) return str;
return Qnil;
}