Summary of methods for manipulating strings using the NSString class in Objective-c _ios

One, string cutting
1, with a node string, such as @ "<p> hate node <br/></p>" We just want the middle of the Chinese

Processing method:

Copy Code code as follows:

NSString *string1 = @ "<p> hate node <br/></p>";

/* Here will not want to put all the characters in the CharacterSet1, do not need another comma or a space, and so on, unless the string you want to remove the space, here < P/And so are separate, not as the entire character * *

Nscharacterset *characterset1 = [Nscharacterset charactersetwithcharactersinstring:@ "<p/brh>"];

Split the string1 by the elements in CharacterSet1

Nsarray *array1 = [string1 componentsseparatedbycharactersinset:characterset1];

NSLog (@ "array =%@", array1);

For (NSString *string1 in array1)
{
if ([string1 length]>0) {

Here string is the Chinese string

NSLog (@ "string =%@", string1);
}
}

Print results:

2016-01-17 10:55:34.017 string[17634:303] 
array = ("
 ",
 "", ""
 ,
 "\u8ba8\u538c\u7684\u8282\ U70b9 "," "
 ,
 " ",
 " ",
 " "," "",
 "",
 "
", "", "" "," "," "," "," 2016-01-17 10:55:34.049 string[17634:303] 
string = annoying node

2, with a space string, such as

@ "Hello World" remove space

Copy Code code as follows:

NSString *string2 = @ "Hello world";

/* Processing Space * *

Nscharacterset *characterset2 = [Nscharacterset whitespacecharacterset];

Split the string1 by the elements in CharacterSet1
Nsarray *array2 = [string2 Componentsseparatedbycharactersinset:characterset2];

NSLog (@ "\narray =%@", array2);

Used to store the processed string
nsmutablestring *newstring1 = [nsmutablestring string];

For (NSString *string in array1)
{
[NewString1 appendstring:string];
}
NSLog (@ "newstring =%@", newString1);

Print results:

2016-01-17 11:02:49.656 string[17889:303] 
array = (
 Hello,
 world
)
2016-01-17 11:02:49.657 string[17889:303] NewString = HelloWorld

PS: Processing letters and other elements can only change the value of the Nscharacterset.

Copy Code code as follows:

+ (ID) controlcharacterset;

+ (ID) whitespacecharacterset;

+ (ID) whitespaceandnewlinecharacterset;

+ (ID) decimaldigitcharacterset;

+ (ID) lettercharacterset;

+ (ID) lowercaselettercharacterset;

+ (ID) uppercaselettercharacterset;

+ (ID) nonbasecharacterset;

+ (ID) alphanumericcharacterset;

+ (ID) decomposablecharacterset;

+ (ID) illegalcharacterset;

+ (ID) punctuationcharacterset;

+ (ID) capitalizedlettercharacterset;

+ (ID) symbolcharacterset;

+ (ID) newlinecharacterset ns_available (10_5, 2_0);

+ (ID) Charactersetwithrange: (Nsrange) Arange;

+ (ID) charactersetwithcharactersinstring: (NSString *) astring;

+ (ID) charactersetwithbitmaprepresentation: (NSData *) data;

+ (ID) charactersetwithcontentsoffile: (NSString *) fName;

Two, the character will nsarray the elements in the mosaic

Copy Code code as follows:

Nsarray *array = [Nsarray arraywithobjects:@ "Hello", @ "World", nil];

If you want to use,: such as string concatenation, just the following @ "" space into @, or @ ":" Can
NSString *string = [Array componentsjoinedbystring:@ "];

NSLog (@ "string =%@", string);

Print results:

Hello World

Third, intercept the substring:

Here take time as an example, using NSDate to get to the current time, sometimes only need a date or only need time

1, from the beginning of the string to intercept to the specified position, such as

Copy Code code as follows:

Get to Current date time
NSDate *date = [NSDate Date];

Defines the date format, which does not focus on the discussion of NSDate, so it is not detailed and will be discussed in detail later.
NSDateFormatter *dateformatter = [[NSDateFormatter alloc] init];

Set Date format
[Dateformatter setdateformat:@ "Yyyy-mm-dd hh:mm"];

Convert Date to NSString type
NSString *string = [Dateformatter stringfromdate:date];
NSLog (@ "\ncurrent =%@", string);

Intercept Date Substringtoindex
NSString *currentdate = [string substringtoindex:10];

NSLog (@ "\ncurrentdate =%@", currentdate);

Print results:

Current = 2016-01-1711:12


currentdate = 2016-01-17

2. Extract the middle substring-substringwithrange

Copy Code code as follows:

Lunar Day of interception
NSString *currentmonthanddate = [String Substringwithrange:[nsmakerange (5, 5)]];

NSLog (@ "currentmonthanddate =%@", currentmonthanddate);

Print results:

Currentmonthanddate = 06-27

3, from a certain location to intercept-Substringfromindex

Copy Code code as follows:

Intercept Time Substringfromindex
NSString *currenttime = [string substringfromindex:11];

NSLog (@ "\ncurrenttime =%@", currenttime); \

Print results:

CurrentTime = 11:25

Iv. Comparing strings

Copy Code code as follows:

NSString *first = @ "string";
NSString *second = @ "String";

1, to determine whether two strings are the same-isequaltostring method

Copy Code code as follows:

BOOL isequal = [Isequaltostring:second];

NSLog (@ "Equal to second:%@", isequal);

Print results:

The Equal to second:0

2, compare method comparison string three values

Copy Code code as follows:

nsorderedsame//is the same
nsorderedascending//Ascending, in alphabetical order, greater than true
nsordereddescending//Descending, in alphabetical order, less than true

BOOL result = [Compare:sencond] = = Nsorderedsame;
NSLog (@ "result:%d", result);

Print results:

result:0 

Copy Code code as follows:

BOOL result = [Compare:second] = = nsorderedascending;
NSLog (@ "result:%d", result);

Print results:

result:0

Copy Code code as follows:

BOOL result = [Compare:second] = = nsordereddecending; NSLog (@ "result:%d", result);

Print results:

Result:1

3. Do not consider case comparison string

Copy Code code as follows:

BOOL result = [Compare:second
Options:nscaseinsensitivesearch | Nsnumericsearch] = = Nsorderedsame;
NSLog (@ "result:%d", result);

Print results:

Result:1

V. Changing the case of strings

Copy Code code as follows:

NSString *astring = @ "A String";
NSString *string = @ "string";
Capital
NSLog (@ "astring:%@", [astring uppercasestring]);
Lowercase
NSLog (@ "string:%@", [string lowercasestring]);
Case of First letter
NSLog (@ "string:%@", [string capitalizedstring]);

Print results:

Astring:a STRING

string:string

string:string

Searching for substrings in strings

Copy Code code as follows:

NSString *string1 = @ "This is a string";
NSString *string2 = @ "string";
Nsrange range = [string1 rangeofstring:string2];
Nsuinteger location = range.location;
Nsuinteger leight = range.length;
NSString *astring = [[NSString alloc] initwithstring:[nsstring stringwithformat:@ "Location:%li,leight:%li", Location, Leight]];
NSLog (@ "astring:%@", astring);
[Astring release];

Print results:

Astring:location:10,leight:6