Summary of common operation methods for string NSString in Objective-c _ios

1. Create a string

(1) Constant string

 code as follows:

NSString *string = @ "I am an iosdevtip!";

(2) Common methods of Creation

 code as follows:

NSString *string = [[NSString alloc] init];

string = @ "I am an iosdevtip too!";

(3) Create a string with initwithstring 

 code as follows:

NSString *string = [[NSString alloc] initwithstring:@ "Iosdevtip is here!"];

2. Format the creation of a string

(1) INT format string

 code as follows:

int age = 20;
NSString *personage = [NSString stringwithformat:@ ' This person ' is%d ', age];

Since int formats strings, float, double, and so on, can also format strings.

(2) NSString format string

code as follows:

NSString *name = @ "Iosdevtip";
NSString *personname = [NSString stringwithformat:@ "This person name is%@", name];

3. String comparison

(1) Comparison of isequaltostring methods

 code as follows:

NSString *stingone = @ "This is a iosdevtip!";
NSString *stringtwo = @ "This is a iosdevtip!";
BOOL result = [Stingone isequaltostring:stringtwo];

(2) Comparison of compare methods

 code as follows:

BOOL result = [Stingone compare:stringtwo] = = Nsorderedsame;

Compare: Method return value type is Nscomparisonresult. And Nscomparisonresult has the following enumeration values.

 code as follows:

typedef ns_enum (Nsinteger, nscomparisonresult) {nsorderedascending = -1l, Nsorderedsame, nsordereddescending};

4. String capitalization conversion

(1) Lowercase to uppercase

 code as follows:

NSString *string = @ "This is a iosdevtip!";
[String lowercasestring];

(2) Uppercase to lowercase

 code as follows:

NSString *string = @ "This is a iosdevtip!";
[String uppercasestring];

(3) Capitalize first letter

 code as follows:

NSString *string = @ "Ligang";
NSLog (@ "string:%@", [string capitalizedstring]);

Print:

2015-07-16 23:06:11.652 iosstrongdemo[10279:3062010] String:ligang

5. Intercept string

(1) Substringtoindex intercept string

 code as follows:

NSString *string = @ "This is a operation string!";
NSString *subtostring = [string Substringtoindex:6];

(2) The intercepted subtostring is this I

Substringfromindex Intercept string

 code as follows:

NSString *subfromstring = [string Substringfromindex:6];

(3) The intercepted subfromstring is S-a operation string!

Substringwithrange Intercept string

 code as follows:

NSString *rangestring = [String Substringwithrange:nsmakerange (6, 3)];

The intercepted rangestring is S-A!

6. Determine if the string contains another string

(1) Rangeofstring judgment

 code as follows:

NSString *string1 = @ "This is a iosdevtip";
NSString *string2 = @ "Iosdevtip";
Nsrange range = [string1 rangeofstring:string2];
Nsinteger location = range.location;
Nsinteger leight = range.length;
NSString *logstring = [[NSString alloc] initwithstring:[nsstring stringwithformat:@ "Location:%ld,leight:%ld", Location,leight]];
NSLog (@ "logstring:%@", logstring);

Print out:

IOSSTRONGDEMO[8837:2221170] Logstring:location:10,leight:9

(2) Determine if the prefix is included

 code as follows:

NSString *string = @ "I Love";
BOOL Ishasi = [string hasprefix:@ "I"];
BOOL Ishaschina = [string hassuffix:@ "in"];

7. Split string

 code as follows:

NSString *string = @ "This is a iosdevtip";
Nsarray *array = [string componentsseparatedbystring:@ "a"];
NSString *string1 = [array objectatindex:0];
NSString *string2 = [array objectatindex:1];
NSLog (@ "string1:%@ string2:%@", string1,string2);

Print:

2015-07-16 22:40:39.559 iosstrongdemo[10165:3055448] String1:this is  string2:iosdevtip

8. Insert String

 code as follows:

nsmutablestring *string = [[Nsmutablestring alloc] initwithstring:@ "I"];
[String insertstring:@ "Love" atindex:2];
NSLog (@ "string:%@", string);

Print:
2015-07-16 22:44:10.706 iosstrongdemo[10206:3057014] string:i Love
(1) Append string

Copy Code code as follows:

nsmutablestring *string = [[Nsmutablestring alloc] initwithstring:@ "I Love"];
[String appendstring:@ "in"];
NSLog (@ "string:%@", string);

Print:

2015-07-16 22:42:32.305 iosstrongdemo[10189:3056410] String:i Love

9. Delete string

Copy Code code as follows:

nsmutablestring *string = [[Nsmutablestring alloc] initwithstring:@ "I Love"];
[String Deletecharactersinrange:nsmakerange (2, 4)];
NSLog (@ "String1:%@", string);

Print:

2015-07-16 22:46:58.437 iosstrongdemo[10219:3057749] String1:i

10. Replacement string

code as follows:

NSString *string = @ "I Love";
NSString *replacestring = [string stringbyreplacingoccurrencesofstring:@ ' love ' withstring:@ ' like '];
NSLog (@ "replacestring:%@", replacestring);

Print:

2015-07-16 22:56:07.405 iosstrongdemo[10236:3059503] replacestring:i like

11. Remove the end of a string of spaces and line breaks

code as follows:

NSString *string = @ "I Love";
NSString *text = [string Stringbytrimmingcharactersinset:[nscharacterset whitespaceandnewlinecharacterset]];
NSLog (@ "text:%@", text);

Print:

2015-07-16 23:00:47.845 iosstrongdemo[10265:3061013] text:i Love