Related usages of the NSString class

One, nsstring string connection
nsstring* string; Result string

nsstring* string1, string2; A string that already exists

1. String = [NSString initwithformat:@ "%@,%@", string1, string2];
2. String = [string1 stringbyappendingstring:string2];</p>
3. string = [string stringbyappendingformat:@ "%@,%@", string1, string2];

4. string = [string stringbyappendingformat:@ "%@%@%@%@%@%@", string1, string2, String3, String4 ...];

Can be spliced a lot,%@ in the middle of a comma string also with a comma

Ii. usage of nnstring

----- methods for creating strings-----//1, create constant string NSString *astring = @ "This is a string!"; 2, first create an empty string, and then assign the value;//Alloc and init combination is suitable for passing parameters between functions, after the use of manual release NSString *astring = [[NSString alloc] init];
Astring = @ "This is a string!";
NSLog (@ "astring:%@", astring);
[Astring RELEASE];//3, in the above method, lifting Speed: Initwithstring method NSString *astring = [[NSString alloc] initwithstring:@ "This is a Str Ing! "];
NSLog (@ "astring:%@", astring);
[Astring release];
4, create temporary string nsstring *astring;
astring = [NSString stringwithcstring: "This is a temporary string"];
NSLog (@ "astring:%@", astring),//OR NSString * scriptstring = [NSString stringwithstring:@ "Tell application \" Mail\ "\ r "];//5, creating a formatted string: placeholder (consisting of a% plus one character) int i = 1;
int j = 2;
NSString *astring = [[NSString alloc] initwithstring:[nsstring stringwithformat:@ "%d.this is%i string!", I,j]];
NSLog (@ "astring:%@", astring);
[Astring release];

----- reading a string from a file -----
NSString *path = @ "Astring.text";
NSString *astring = [[NSString alloc] initwithcontentsoffile:path];
NSLog (@ "astring:%@", astring);
[Astring release];

-----write string to file----
NSString *astring = [[NSString alloc] initwithstring:@ "This is a string!"];
NSLog (@ "astring:%@", astring);
NSString *path = @ "Astring.text";
[astring Writetofile:path Atomically:yes];
[Astring release];
-----comparison of two strings-----
1. Comparison with C: strcmp function
Char string1[] = "string!";
Char string2[] = "string!";
if (strcmp (string1, string2) = = 0)
{
NSLog (@ "1");
}
2. Isequaltostring method
NSString *ASTRING01 = @ "This is a string!";
NSString *astring02 = @ "This is a string!";
BOOL result = [Astring01 isequaltostring:astring02];
NSLog (@ "result:%d", result);
3. Compare method (three values returned by comparer: nsorderedsame,nsorderedascending,nsordereddescending)
NSString *ASTRING01 = @ "This is a string!";
NSString *astring02 = @ "This is a string!";
BOOL result = [Astring01 compare:astring02] = = Nsorderedsame; Nsorderedsame judge whether the two are the same
NSLog (@ "result:%d", result);

NSString *ASTRING01 = @ "This is a string!";
NSString *astring02 = @ "This is a string!";
BOOL result = [Astring01 compare:astring02] = = nsorderedascending;
NSLog (@ "result:%d", result);
Nsorderedascending determines the size of two object values (in alphabetical order, astring02 greater than ASTRING01 is true)

NSString *ASTRING01 = @ "This is a string!";
NSString *astring02 = @ "This is a string!";
BOOL result = [Astring01 compare:astring02] = = nsordereddescending;
NSLog (@ "result:%d", result);
Nsordereddescending determines the size of two object values (in alphabetical order, ASTRING02 is less than astring01 true)
4, do not consider case comparison string 1
NSString *ASTRING01 = @ "This is a string!";
NSString *astring02 = @ "This is a string!";
BOOL result = [Astring01 caseinsensitivecompare:astring02] = = Nsorderedsame;
NSLog (@ "result:%d", result);
Nsordereddescending determines the size of two object values (in alphabetical order, ASTRING02 is less than astring01 true)
5, do not consider case comparison string 2
NSString *ASTRING01 = @ "This is a string!";
NSString *astring02 = @ "This is a string!";
BOOL result = [Astring01 compare:astring02
Options:nscaseinsensitivesearch | Nsnumericsearch] = = Nsorderedsame;
NSLog (@ "result:%d", result);
Nscaseinsensitivesearch: Case-insensitive comparison nsliteralsearch: Make a full comparison, case-sensitive nsnumericsearch: Compares the number of characters in a string, not the character value.

Third, print the log

NSLog (@ "%@", order);//Print Dictionary

NSLog (@ "%@", imageurlstring);

Related usages of the NSString class