String Modify Methods in Java|substring(), concat(), replace(), trim(), toUpperCase(), toLowerCase()

substring(int beginIndex)
Returns a string that is a substring of this string.
substring(int beginIndex, int endIndex)
Returns a string that is a substring of this string.
concat(String str)
Concatenates the specified string to the end of this string.
replace(char oldChar, char newChar)
Returns a string resulting from replacing all occurrences of oldChar in this string with newChar.
replace(CharSequence target, CharSequence replacement)
Replaces each substring of this string that matches the literal target sequence with the specified literal replacement sequence.
trim()
Returns a string whose value is this string, with any leading and trailing whitespace removed.
toUpperCase()
Converts all of the characters in this String to upper case using the rules of the default locale.
toUpperCase(Locale locale)
Converts all of the characters in this String to upper case using the rules of the given Locale.
toLowerCase()
Converts all of the characters in this String to lower case using the rules of the default locale.
toLowerCase(Locale locale)
Converts all of the characters in this String to lower case using the rules of the given Locale.