iOS Learning Road of Objective-c (ii)--string

1. Creation of NSString objects

   1     //Creating immutable Strings2NSString *string1 =@"bei Jing Huan Ying Nin";3 #pragmaThe Mark object method creates a string4     //initializes the current string with another string with the same address as the pointer5NSString *string2 =[[NSString alloc] initwithstring:string1];6     //converting other data types to string types7NSString *string3 = [[NSString alloc] Initwithformat:@"Age was%d, name is%@", at,@"DYK"];8 #pragmaThe Mark class method creates a string9     //the method corresponds to the Initwithstring method .TenNSString *string4 =[NSString stringwithstring:string1]; One     //the method corresponds to the Initwithformat method . ANSString *string5 = [NSString stringWithFormat:@"Age was%d, name is%@", at,@"DYK"];

2. Concatenation of strings

   1NSString *string1 =@"DYK";2NSString *string2 =@"Shuai";3     //-(NSString *) stringbyappendingstring: (NSString *) astring;4     //function: Concatenation of two strings5     //two concatenation of the string has not changed, the return value is the concatenation of the string6NSString *string3 =[string1 stringbyappendingstring:string2];7NSString *string4 = [NSString stringWithFormat:@"%@%@", string1, string2];

4. Evaluates the length of the string

    1  nsstring *string  = @ " zhou Dong Yu   " ;  2  Nsuinteger len = [string  length]; 

6. Remove a reference to a member in a string

   1     NSString *string@ "Zhou Dong yu"; 2     0 ; 3     char character = [string characteratindex:position];

7. Comparison of strings

   1NSString *string1 =@"Chen Chao";2NSString *string2 =@"CHAN CHAO";3 #if04     //-(BOOL) isequaltostring: (NSString *) astring;5     //function: Compare two strings are identical6     //Bool:yes (True), NO (false)7BOOL BL =[string1 isequaltostring:string2];8     if(BL) {9NSLog (@"string1 = = string2");Ten}Else{ OneNSLog (@"string1! = string2"); A     } - #endif -      the #if0 -     //-(Nscomparisonresult) Compare: (NSNumber *) Decimalnumber; -     //function: Compares two strings (not ignoring case) -     //nscomparisonresult:nsorderedascending (Ascending) +     //Nsorderedsame (same) -     //nsordereddescending (Descending) +Nscomparisonresult result =[string1 compare:string2]; A     if(Result = =nsordereddescending) { atNSLog (@"String1 < string2"); -}Else if(Result = =nsorderedascending) { -NSLog (@"string1 > string2"); -}Else { -NSLog (@"string1 = = string2"); -     } in #endif -     //-(Nscomparisonresult) Caseinsensitivecompare: (NSString *) string; to     //function: Compares two strings for the same (ignoring case) +Nscomparisonresult result =[string1 caseinsensitivecompare:string2]; -     if(Result = =nsordereddescending) { theNSLog (@"String1 < string2"); *}Else if(Result = =nsorderedascending) { $NSLog (@"string1 > string2");Panax Notoginseng}Else { -NSLog (@"string1 = = string2"); the}

8. Find the location of a substring in a string

   1NSString *string1 =@"Chen Chao Zui shuai";2NSString *string2 =@"Zui";3     4     //-(Nsrange) rangeofstring: (NSString *) astring;5     //function: Find the location of a substring in a string6     //typedef struct _NSRANGE {7     //Nsuinteger location; Start position8     //Nsuinteger length; Length starting from the starting position9     //} nsrange;TenNsrange range =[string1 rangeofstring:string2]; One     if(Range.location = =nsnotfound) { ANSLog (@"not found"); -     } -NSLog (@"Location was%lu, length is%lu", Range.location, range.length);

iOS Learning Road of Objective-c (ii)--string