Is it possible to extend java lang string

String class overrides equals method and provides a content equality, which is based on characters, case and order. So if you want to compare two String object, to check whether they are same or not, always use equals method instead of equality operator. Like in earlier example if we use the equals method to compare objects, they will be equal to each other because they all contain the same contents.

Here is example of comparing String using equals method. String class in Java provides convenient method to see if a character or sub-string or a pattern exists in current String object. You can use indexOf which will return position of character or String, if that exist in current String object or -1 if character doesn't exists in String.

String class. Remember matches is tricky and some time non-intuitive. If you just put "Java" in matches it will return false because String is not equals to "Java" i. See here for more examples of String matches method.

Apart from indexOf , lastIndexOf and matches String regex String also has methods like startsWith and endsWidth , which can be used to check an String if it starting or ending with certain character or String. Java String provides another useful method called substring , which can be used to get parts of String.

Index starts from 0 and goes till String. By the way String. One point which is worth remembering here is that substring is also backed up by character array, which is used by the original String. This can be dangerous if the original string object is very large and substring is very small because even a small fraction can hold reference of the complete array and prevents it from being garbage collected even if there is no other reference for that particular String.

Read How Substring works in Java for more details. Here is an example of using SubString in Java:. It can even be used to convert int , char , long or double to convert into String by simply concatenating with empty string "". Since both represent mutable object they can be used to reduce string garbage created because of temporary String. Read more about StringBuffer vs StringBuilder here. String in Java provides a trim method to remove white space from both end of String.

If trim removes white spaces it returns a new String otherwise it returns same String. Along with trim String also provides replace and replaceAll method for replacing characters from String. Read more about How to replace String in Java here. String in Java is feature-rich. There are other methods also available related to splitting String, see this Java tutorial to split string for more details.

String pose a security threat if used for storing sensitive data like passwords, SSN or any other sensitive information. Since String is immutable in Java there is no way you can erase contents of String and since they are kept in the String pool in case of String literal they stay longer on Java heap, which exposes the risk of being seen by anyone who has access to Java memory, like reading from the memory dump.

Instead, char[] should be used to store passwords or sensitive information. See Why char[] is more secure than String for storing passwords in Java for more details. It does not make sense to have a String without knowing what encoding it uses. There is no way to interpret a String if you don't know the encoding it used. If you have a String, in memory or stored in file, you must know what encoding it is in, or you cannot display it correctly.

By default Java uses platform encoding i. Returns: the character at the specified index of this string. The first character is at index 0. The first character to be copied is at index srcBegin ; the last character to be copied is at index srcEnd-1 thus the total number of characters to be copied is srcEnd-srcBegin.

Copies characters from this string into the destination byte array. Each byte receives the 8 low-order bits of the corresponding character. The first character to be copied is at index srcBegin ; the last character to be copied is at index srcEnd The total number of characters to be copied is srcEnd-srcBegin. Returns: the resultant byte array. The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object.

Parameters: anObject - the object to compare this String against. Returns: true if the String are equal; false otherwise.

Overrides: equals in class Object See Also: compareTo java. String , equalsIgnoreCase java. The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object, where case is ignored. Applying the method Character. Two sequences of characters are the same, ignoring case, if the sequences have the same length and corresponding characters are the same, ignoring case.

Parameters: anotherString - the String to compare this String against. Returns: true if the String s are equal, ignoring case; false otherwise. See Also: Character. The comparison is based on the Unicode value of each character in the strings. Parameters: anotherString - the String to be compared. Returns: the value 0 if the argument string is equal to this string; a value less than 0 if this string is lexicographically less than the string argument; and a value greater than 0 if this string is lexicographically greater than the string argument.

If the Object is a String, this function behaves like compareTo String. Specified by: compareTo in interface Comparable Parameters: o - the Object to be compared. Returns: the value 0 if the argument is a string lexicographically equal to this string; a value less than 0 if the argument is a string lexicographically greater than this string; and a value greater than 0 if the argument is a string lexicographically less than this string. Throws: ClassCastException - if the argument is not a String.

The comparison is based on the Unicode value of each character in the string converted to lower case as by Character. Note that this method is does not take locale into account, and may not result in a satisfactory ordering for certain locales. Parameters: str - the String to be compared. Returns: a negative integer, zero, or a positive integer as the the specified String is greater than, equal to, or less than this String, ignoring case considerations. Parameters: toffset - the starting offset of the subregion in this string.

Returns: true if the specified subregion of this string exactly matches the specified subregion of the string argument; false otherwise. Parameters: ignoreCase - if true , ignore case when comparing characters. Returns: true if the specified subregion of this string matches the specified subregion of the string argument; false otherwise.

Whether the matching is exact or case insensitive depends on the ignoreCase argument. Parameters: prefix - the prefix. String byte[] bytes, String charsetName This constructs a new String by decoding the specified array of bytes using the specified charset. String char[] value This allocates a new String so that it represents the sequence of characters currently contained in the character array argument.

String char[] value, int offset, int count This allocates a new String that contains characters from a subarray of the character array argument. String int[] codePoints, int offset, int count This allocates a new String that contains characters from a subarray of the Unicode code point array argument.

String String original This initializes a newly created String object so that it represents the same sequence of characters as the argument; in other words, the newly created string is a copy of the argument string. String StringBuffer buffer This allocates a new string that contains the sequence of characters currently contained in the string buffer argument.

String StringBuilder builder This allocates a new string that contains the sequence of characters currently contained in the string builder argument. String concat String str This method concatenates the specified string to the end of this string. String intern This method returns a canonical representation for the string object.

String replace char oldChar, char newChar This method returns a new string resulting from replacing all occurrences of oldChar in this string with newChar. String replace CharSequence target, CharSequence replacement This method replaces each substring of this string that matches the literal target sequence with the specified literal replacement sequence. String replaceAll String regex, String replacement This method replaces each substring of this string that matches the given regular expression with the given replacement.

String replaceFirst String regex, String replacement This method replaces the first substring of this string that matches the given regular expression with the given replacement.

String[] split String regex This method splits this string around matches of the given regular expression. String[] split String regex, int limit This method splits this string around matches of the given regular expression. CharSequence subSequence int beginIndex, int endIndex This method returns a new character sequence that is a subsequence of this sequence. String substring int beginIndex This method returns a new string that is a substring of this string.

String substring int beginIndex, int endIndex This method returns a new string that is a substring of this string. Well, thanks everybody. Appreciate it. John Muczynski. If someone is really making a class which is a string implementation, then you might consider implementing the CharSequence interface. You can add it with strings for example.

Perhaps you'd like to take a look at the StringBuilder class? Stephan van Hulst. Saloon Keeper. Campbell Ritchie. Campbell Ritchie You're asking me if I realized it was a 5 year old thread? Or Stephan? That's why I started with "If someone is" Lots of people like me do a search and get a page like this. Winston Gutkowski. In which case I suspect you're right: CharSequence sounds ideal.

I was also interested in the "ropes" link. I ran into it a while back, and didn't give it much thought; but I'm now wondering if there might not be a much simpler implementation possible based on a SkipList which are, by definition, self-balancing.