Common usage of iOS strings

Creates a new string and sets it to the contents of the file specified by path, uses the character encoding enc, and returns an error on the error

+ (ID) Stringwithcontentsofurl: (nsurl *) URL encoding: (nsstringencoding) ENC error: (NSERROR *) error;

Creates a new string and sets it to the content specified by the URL, uses character encoding enc, and returns an error on the error
+ (ID) stringwithcontentsoffile: (NSString *) path encoding: (nsstringencoding) ENC error: (NSERROR *) error;

Create a new empty string

+ (ID) string

Creates a new string and sets its contents to the contents of a string

+ (ID) stringwithstring: (NSString *) string;

Set the newly assigned string to the contents of astring

-(ID) initwithstring: (NSString *) astring;

Set the string to the contents of the file specified by path using character encoding enc and returning an error on the error

-(ID) Initwithcontentsoffile: (NSString *) path encoding: (nsstringencoding) ENC error: (NSERROR *) error;

Set the string to the contents of the file specified by path using character encoding enc and returning an error on the error

-(ID) Initwithcontentsofurl: (nsurl *) URL encoding: (nsstringencoding) ENC error: (NSERROR *) error;

Returns the number of characters in a string

-(nsuinteger) length;

Returns the Unicode character where the index (a value, such as I) resides
-(Unichar) Characteratindex: (Nsuinteger) index;

Return from (?) Start to end substring

-(NSString *) Substringfromindex: (Nsuinteger) from;

Returns the position from the beginning of the string to the (?) Substring of
-(NSString *) Substringtoindex: (Nsuinteger) to;

Returns a substring based on a specified range
-(NSString *) Substringwithrange: (nsrange) range;

Compare two strings (ignoring case)

-(Nscomparisonresult) Caseinsensitivecompare: (NSString *) string;

Comparison of two strings

-(Nscomparisonresult) Localizedcompare: (NSString *) string;

Test whether the string starts with astring

-(BOOL) Hasprefix: (NSString *) astring;

Test whether the string ends with astring

-(BOOL) Hassuffix: (NSString *) astring;

Tests whether two strings are equal

-(BOOL) isequaltostring: (NSString *) astring;

Returns the first letter of each word in string strings, with the remaining letters lowercase

-(NSString *) capitalizedstring;

Returns a string converted to lowercase

-(NSString *) lowercasestring;

Returns a string converted to uppercase

-(NSString *) uppercasestring;

Returns a string converted to UTF8 encoded format

-(__strong const char *) utf8string;

Returns a string that converts a double type

-(double) doublevalue;

Returns a string that converts a float type

-(float) floatvalue;

Returns a string that converts the type int

-(int) intvalue;

Returns a string converted to the Nsinteger type

-(Nsinteger) IntegerValue