PHP实现字符串大小写转函数的功能实例

//字符转大写protected function toupper($c){
$ord = ord($c);
return $ord>=97 && $ord<=122 ?chr($ord-32):$c;}//字符转小写protected function tolower($c){
$ord = ord($c);
return $ord>=65 && $ord<=90 ?chr($ord+32):$c;}

public function strtolower($str){
 if($this->checkempty($str))
 {
 return "";
 }
 $len = strlen($str);
 for($i=0;$i<$len;$i++){
 $str[$i] = $this->tolower($str[$i]);
 }
 return $str;}

public function ucfirst($str){
 if($this->checkempty($str))
 {
 return "";
 }
 $str[0] = $this->toupper($str[0]);
 return $str;}

public function lcwords($str){
 if($this->checkempty($str))
 {
 return "";
 }
 $splitchar = [' ',"\n","\r","\f","\v"];
 $len = strlen($str);
 for($i=0;$i<$len;$i++){
 if(in_array($str[$i], $splitchar))
 {
 $i++;
 if($i>=$len)
 {
 break;
 }
 $str[$i] = $this->tolower($str[$i]);
 }
 }
 return $str;}

PHP_FUNCTION(ucwords){
 zend_string str;
 char delims = " \t\r\n\f\v";
 register char r, r_end;
 size_t delims_len = 6;
 char mask[256];

 ZEND_PARSE_PARAMETERS_START(1, 2)
 Z_PARAM_STR(str)
 Z_PARAM_OPTIONAL Z_PARAM_STRING(delims, delims_len)
 ZEND_PARSE_PARAMETERS_END();

 if (!ZSTR_LEN(str)) {
 RETURN_EMPTY_STRING();
 }
 php_charmask((unsigned char )delims, delims_len, mask);

 ZVAL_STRINGL(return_value, ZSTR_VAL(str), ZSTR_LEN(str));
 r = Z_STRVAL_P(return_value);

 r = toupper((unsigned char) r);
 for (r_end = r + Z_STRLEN_P(return_value) - 1; r < r_end; ) {
 if (mask[(unsigned char)r++]) {
 r = toupper((unsigned char) r);
 }
 }}