Lower case the first letter of the given string.

@param _str string
@return lowercased string
343134
public static String lowerCaseFirstChar(String _str) {
        if (_str == null) {
            return null;
        }
        if (_str.isEmpty()) {
            return _str;
        }

        return _str.substring(0, 1).toLowerCase() + _str.substring(1);
    }
171033
public static function low($string): string
    {
        $cleaned = Str::low($string);
        $cleaned = Str::trim($cleaned);

        return $cleaned;
    }
998697
def snake_case(str)
      return str.downcase if str.match(/\A[A-Z]+\z/)
      str.gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2').
        gsub(/([a-z])([A-Z])/, '\1_\2').
        downcase
    end
1311341
public static function toCamelCase(string $str, bool $upperFirst = false): string
    {
        $str = (string)self::strtolower($str);

        if ($upperFirst) {
            $str = self::ucfirst($str);
        }

        return \preg_replace_callback('/_+([a-z])/', function ($c) {
            return \strtoupper($c[1]);
        }, $str);
    }
159200
public static String underScore2CamelCase(String strs) {

        if (strs == null || !strs.contains("_")) {
            return strs;
        }
        StringBuilder sb = new StringBuilder("");
        String[] elems = strs.split("_");
        for (int i = 0; i < elems.length; i++) {
            String elem = elems[i].toLowerCase();
            if (i != 0) {
                char first = elem.toCharArray()[0];
                sb.append((char) (first - 32)).append(elem.substring(1));
            } else {
                sb.append(elem);
            }
        }
        return sb.toString();
    }
658997
String convertCase(String str) {
        if (str == null) {
            return null;
        }
        return sensitive ? str : str.toLowerCase();
    }
893148
function lowercase(arr) {
  var ret = new Array(arr.length);

  for (var i = 0; i < arr.length; ++i) {
    ret[i] = String(arr[i]).toLowerCase();
  }

  return ret;
}
1282834
private function underlineToUppercase($str)
    {
        $fnc = function ($matches) {
            return strtoupper($matches[1]);
        };
        $str = preg_replace_callback('/_+([a-z])/', $fnc, $str);
        return $str;
    }
1061176
public static function lower($str, $encoding = null) {
        $encoding or $encoding = \Fuel::$encoding;
        return function_exists('mb_strtolower') ? mb_strtolower($str, $encoding) : strtolower($str);
    }
700233
@NotNull
    private static String getLowerCaseString(@NotNull final String string) {
        return StringUtils.strip(string).toLowerCase();
    }
10669
public static String toLowerCaseWithUnderscore(final String str) {
        if (N.isNullOrEmpty(str)) {
            return str;
        }

        String result = lowerCaseWithUnderscorePropNamePool.get(str);

        if (result == null) {
            result = StringUtil.toLowerCaseWithUnderscore(str);
            lowerCaseWithUnderscorePropNamePool.put(str, result);
        }

        return result;
    }
1281524
func LowerCaseFirst(s string) string {
	if len(s) == 0 {
		return s
	}
	return string(s[0]|' ') + s[1:]
}
1272721
function ucFirst( str ) {
		str += '';
		var f = str.charAt( 0 ).toUpperCase();
		return f + str.substr( 1 );
	}
167952
private static function underscore2CamelCase($str)
    {
        // Non-alpha and non-numeric characters become spaces.
        $str = preg_replace('/[^a-z0-9]+/i', ' ', $str);
        // Uppercase the first character of each word.
        $str = ucwords(trim($str));
        // Remove all spaces.
        $str = str_replace(" ", "", $str);
        // Lowercase the first character of the result.
        $str[0] = strtolower($str[0]);

        return $str;
    }
21790
function camelCase(str) {
    return str
        .replace(/[-_\s]+(.)/gu, (_, c) => c.toUpperCase())
        .replace(/^./u, c => c.toLowerCase())
}
74633
private function toCamelCase($str): string
    {
        $func = function ($c) {
            return strtoupper($c[1]);
        };

        return preg_replace_callback('/_([a-z])/', $func, $str);
    }
711807
public static function Ucfirst($str)
    {
        return function_exists('ucfirst') ?
            ucfirst($str) :
            static::Upper(substr($str, 0, 1)).substr($str, 1);
    }