字符串所有字符是否全部是字母

@param string 字符串

@return {@link Boolean}

@since 1.0.9
176513
public static boolean isLetter(String string) {
        boolean result = isNotEmpty(string);
        int idx = 0;
        int len = string.length();
        while (result) {
            if (idx >= len) {
                break;
            }
            result = isLetter(string.charAt(idx));
            idx++;
        }
        return result;
    }
139078
public List<String[]> getAllMatches(String string) {
		Matcher matcher = pattern.matcher(string);
		List<String[]> matched = new ArrayList<String[]>();
		while(matcher.find()) {
			int count = matcher.groupCount();
			String [] strings = new String[count];
			for(int i = 0; i < count; ++i) {
				strings[i] = matcher.group(i+1);				
			}
			matched.add(strings);
		} 
		return matched;
	}
718254
@Override
	public boolean contains(String str) {
		int[] positions = createHashes(str, hashFunctionNumber);
		for (int i : positions) {
			int position = Math.abs(i % bitSetSize);
			if (!bitSet.get(position)) {
				return false;
			}
		}
		return true;
	}
382649
private static String validFunction( String string)
    {
    return
      GeneratorSet.ALL.equals( string)
      ? string
      : validIdentifier( string);
    }
257338
public static boolean isAllNumber(String str) {
    	boolean hasNumber = false;
		for (int i = 0; i < str.length(); i++) {
		    if (!(Character.isDigit(str.charAt(i)) || 
				str.charAt(i) == '.' || str.charAt(i) == ',' || str.charAt(i) == '%'
				|| str.charAt(i) == '$' || str.charAt(i) == '_')) {
			return false;
		    }
		    else if (Character.isDigit(str.charAt(i)))
		    	hasNumber = true;
		}
		
		if (hasNumber == true)
			return true;
		else return false;		
    }
1052530
public static boolean isBlank(final String string) {
        if (string == null || string.isEmpty())
            return true;

        return string.chars().allMatch(Character::isWhitespace);
    }
1326499
public static boolean isNullOrEmpty(@Nullable String string)
  {
    if (string == null || string.isEmpty())
    {
      return true;
    }
    return false;
  }
137999
public static boolean isAllAlpha(String str) {

	if (str == null) return false;

	for (int i = str.length() - 1; i >= 0; i--) {

	    if (!Character.isLetter(str.charAt(i))) return false;
	}

	return true;
    }
1194274
function( string ) {
    var negated, matches, patterns = this.patterns, i = patterns.length;
    while ( i-- ) {
      negated = patterns[ i ].negated;
      matches = patterns[ i ].matcher( string );
      if ( negated !== matches ) {
        return matches;
      }
    }
    return false;
  }
80868
public static int count(final String string, final String substring)
   {
      int count = 0;
      int idx = 0;

      while ((idx = string.indexOf(substring, idx)) != -1)
      {
         idx++;
         count++;
      }

      return count;
   }
1101263
public function contains($string): bool
    {
        try {
            Assert::typeOf(['string', __CLASS__], $string);
        } catch (InvalidArgumentException|TypeError $t) {
            return false;
        }

        return mb_strpos($this->data, (string) $string, 0, $this->encoding) !== false;
    }
697443
public static function getBoolean($string) {
    $val = filter_var($string, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
    if ($val === null) {
      return $string;
    }
    return $val;
  }
293657
private boolean parseBoolean(String s) {
        if ( "1".equals(s) ) {
            return true;
        } else if ( "0".equals(s) ) {
            return false;
        } else {
            throw new IllegalArgumentException("Expected 1 or 0 for boolean value, was " + s);
        }
    }
96433
public static final Boolean parseBoolean(String value)
   {
      return (value == null || value.charAt(0) != '1' ? Boolean.FALSE : Boolean.TRUE);
   }
686166
@Override
	public boolean contains(String str) {
		for (BloomFilter filter : filters) {
			if (filter.contains(str) == false) {
				return false;
			}
		}
		return true;
	}
1153700
public static function isBoolean($string)
    {
        if (gettype($string) === 'string') {
            $string = self::toLowerTrim($string);
            if ($string == 'true') {
                return true;
            } elseif ($string == 'false') {
                return true;
            } else {
                return false;
            }
        } else {
            return false;
        }
    }
319602
public static boolean isInteger(String string)
  {
    if(string == null || string.isEmpty()) return false;
    int startIndex = string.charAt(0) == '-' ? 1 : string.charAt(0) == '+' ? 1 : 0;
    for(int i = startIndex, l = string.length(); i < l; i++) {
      if(string.charAt(i) == GROUPING_SEPARATOR) continue;
      if(!Character.isDigit(string.charAt(i))) {
        return false;
      }
    }
    return true;
  }