The String class is final, and any change to the String class will return a new String class object. In this way, the reference of the String class is passed to a method, and any modification of the String by this method has no effect on the object pointed by the original reference, similar to the basic data type.
Extended data:
Members provided by the String class perform the following operations: compare String objects; Returns the index of a character or string in a string object; Copy the value of a string object; Separated or combined strings; Modify the value of the string; Format numbers; Date and time; Or an enumeration value in the form of a string; Normalize a string.
Use the Compare, CompareOrdinal, CompareTo, Equals, EndsWith and StartsWith methods for comparison.
Use the IndexOf, IndexOfAny, LastIndexOf and LastIndexOfAny methods to get the index of a substring or Unicode character in a string.
Use Copy and CopyTo copy a string or substring to another string or an array of type Char.
Use Substring and Split methods to create one or more new strings from the components of the original string; Use Concat and Join methods to create a new string from one or more substrings.
Use Insert, Replace, Remove, PadLeft, PadRight, Trim, TrimEnd and TrimStart to modify all or part of the string.
Use the ToLower, ToLowerInvariant, ToUpper, and ToUpperInvariant methods to change the case of Unicode characters in a string.
Use the Length property to get the number of Char objects in the string; Use the Chars property to access the actual Char object in the string.
Use the IsNormalized method to test whether the string has been normalized to a specific normal form. Use the Normalize method to create a string normalized to a specific normal form.
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