Dark Horse programmer--"Dark Horse video note" OC Language Foundation NSString

1. Creation of strings

   1:  @ "Jack";

   2:      

   3:      //nsstring *s2 = [[NSString alloc] initwithstring:@ "Jack"];

   4:      

   5:      nsstring *s3 = [[NSString alloc] Initwithformat:@ "Age is%d", 10];

   6:      

   7:      //C string > C string

  Ten:      constchar *cs = [S4 utf8string];

  11:      

Nsutf8stringencoding   :      //Use this code in Chinese

  :      nsstring *s5 = [[NSString alloc] Initwithcontentsoffile:@ "/users/apple/desktop /1.txt " encoding:nsutf8stringencoding Error:nil];

  14:      

   1:  /*

   2:        There will always be a class method paired with the object method

   3:       [Nsurl urlwithstring:<# (NSString *) #>];

   4:       [NSString stringwithformat:@ ""];

   5:       [NSString stringwithcontentsoffile:<# (NSString *) #> encoding:<# ( nsstringencoding) #> error:<# (nserror *__autoreleasing *) #>];

   6:       

   7:       * /

2. Common methods

1) Check the prefix

   1:  @ "Qq=12344&pwd=adadfs";

   2:      [str hasprefix:@ "qq="];

   3:      

   4:      [str hassuffix:@ "FS"];

2) uppercase and lowercase conversions

   1:      nsstring *str = [@ "Adbdad" lowercasestring];

   2:      nsstring *upstr = [str uppercasestring];

   3:      NSLog (@ "%@", UPSTR);

   4:      //    [[@ "Adbdad" lowercasestring] isequaltostring:@ "ADSFASD" ];

3) Variable string

   1:     nsmutablestring *str = [[Nsmutablestring alloc] initwithcapacity:0];

   2:      

   3:      [str appendformat:@ "123"];  //123

   4:      //    NSLog (@ "%@", str);

   5:      //

   6:      //    NSString *str1 = @ "123";

   7:      //    NSString *str2 = [str1 stringbyappendingstring:@ "AAAA"];

   8:      //    NSLog (@ "%@", str2);

   9:      //

  :      nsrange rang3 = [str rangeofstring:@ "3"];

One   :      [str deletecharactersinrange:rang3];

  :      NSLog (@ "%@", str);

  13:      

  :      [str insertstring:@ "AAA" atindex:0];

  15:      

+   :      //@ "3" @ ""

+   :      [str replaceoccurrencesofstring:@ "3"

  :                           withstring:@ ""

  :                              Options:nsliteralsearch

  :                                range:nsmakerange (0, str.length)];

  :      NSLog (@ "%@", str);

Dark Horse programmer--"Dark Horse video note" OC Language Foundation NSString