Basic usage of nsstring and nsmutablensstring

////main.m//NSString/** NSString 1.NSString is a non-changeable string Object 2.NSMutableString is a mutable string.  The following code is a string: Add, delete, replace, check method to demonstrate. */#import<Foundation/Foundation.h>voidmutablensstring () {nsmutablestring*mutablestring =[nsmutablestring stringWithFormat:@"I am a mutable string"]; //Add a string to the specified position[Mutablestring insertstring:@"Increase"atindex: ([mutablestring length])]; NSLog (@"%@", mutablestring); //specify a range to replace all strings[Mutablestring Replacecharactersinrange:nsmakerange (0, [mutablestring length]) withstring:@"string after substitution"]; NSLog (@"%@", mutablestring); Nsrange rang= [Mutablestring rangeofstring:@"string"]; [Mutablestring Replacecharactersinrange:rang withstring:@"string"]; NSLog (@"%@", mutablestring); //Reset Variable String contents[Mutablestring setString:@"Abcdaa"]; //Replace A with E, in the form of a size difference[Mutablestring replaceoccurrencesofstring:@"A"Withstring:@"E"Options:nsliteralsearch Range:nsmakerange (0, [mutablestring length])]; NSLog (@"%@", mutablestring); //Delete A string of the specified rangeNsrange Deleterang = [mutablestring rangeofstring:@"a"]; //It is best to decide whether to exist before deleting, or to catch an exception using @try[mutablestring Deletecharactersinrange:deleterang]; NSLog (@"%@", mutablestring);}voidBasestringmeth () {//basic methods of stringsNSString *STR1 =@"Hello NSString"; //length of query stringNsuinteger length=[str1 length]; NSLog (@"length =%lu", length); //Convert UppercaseNSString *uppernsstring =[str1 uppercasestring]; NSLog (@"%@", uppernsstring); //Convert lowercaseNSString *lowernsstring =[str1 lowercasestring]; NSLog (@"%@", lowernsstring); //Character Exchange linksNSString *appendstring =@"study"; NSString*afterappendstring =[appendString STRINGBYAPPENDINGSTRING:STR1]; NSLog (@"%@", afterappendstring); //determine if strings are equalNSString *a =@"string A"; NSString*b =@"String B"; NSString*c =@"string A"; NSString*d =@"String a"; NSString*e =@"Strina a"; if([a isequaltostring:b]! =YES) {NSLog (@"Not Equal"); }    if([a isequaltostring:c]) {NSLog (@"Equal"); }    //This judgment is strictly case-sensitive .    if([a isequaltostring:d]) {NSLog (@"Equal"); }    //string comparison Size, string comparison is actually comparedNSString *compare1=@"1"; NSString*compare2 =@"2"; //-(Nscomparisonresult) Compare: (NSString *) string; The comparison method return value is Nscomparisonresult, and he is an enumeration type//typedef ns_enum (Nsinteger, nscomparisonresult) {nsorderedascending = -1l, Nsorderedsame, nsordereddescending};    if([compare1 compare:compare2] = =nsorderedascending) {NSLog (@"Compare1 <compare2"); }Else if([compare1 compare:compare2] = =nsorderedsame) {NSLog (@"Compare1 ==compare2"); }Else if([compare1 compare:compare2] = =nsordereddescending) {NSLog (@"Compare1 >compare2"); } nsstring*compare3=@"res1"; NSString*compare4 =@"RES1"; if([compare3 compare:compare4] = =nsorderedascending) {NSLog (@"compare3 <compare4"); }Else if([compare3 compare:compare4] = =nsorderedsame) {NSLog (@"compare3 ==compare4"); }Else if([compare3 compare:compare4] = =nsordereddescending) {NSLog (@"compare3 >compare4"); }    //comparison of ignoring uppercase and lowercase    if([compare3 caseinsensitivecompare:compare4] = =nsorderedascending) {NSLog (@"compare3 <compare4"); }Else if([compare3 caseinsensitivecompare:compare4] = =nsorderedsame) {NSLog (@"compare3 ==compare4"); }Else if([compare3 caseinsensitivecompare:compare4] = =nsordereddescending) {NSLog (@"compare3 >compare4"); }        }voidNsstringsearch () {//Searching for stringsNSString *STR1 =@"Hello NSString"; NSString*hello =@"Hello"; //find the location of the Hello stringNsrange Hellorang =[str1 Rangeofstring:hello]; NSLog (@"Hello Location=%lu and Length=%lu", hellorang.location,hellorang.length); NSString*hello2 =@"Hello2"; Nsrange helloRang2=[str1 Rangeofstring:hello2]; //The system returns a nsnotfound when the corresponding string is not found    if(Hellorang2.location = =nsnotfound) {NSLog (@"in%@, the corresponding string is not found%@", Str1,hello2); }    /** Incoming Nsstringcompareoptions enumeration value enum{Nscaseinsensitivesearch = 1,//case insensitive comparison nsliteralsearch = 2,//differentiated Case comparison Nsbackwardssearch = 4,//start Search from the end of the string nsanchoredsearch = 8,//Search restricted string nsnumbericsearch = 64//is based on the number in the string and calculate the order. For example Foo2.txt < Foo7.txt < Foo25.txt//The following definition is higher than Mac OS 10.5 or more than iphone 2.0 available Nsdiacriticinsensitivesearch = 12  8,//ignores the "-" symbol comparison Nswidthinsensitivesearch = 256,//ignores the length of the string, compares the result Nsforcedorderingsearch = 512//ignores the case-insensitive comparison option, and forces the return Nsorderedascending or nsordereddescending//The following definition is higher than the iphone 3.2 available Nsregularexpressionsearch = 1024//can only be applied to Rangeofs Tring: ..., stringbyreplacingoccurrencesofstring: ... and replaceoccurrencesofstring: ... Method. Using a generic compatible comparison method, if you set this, you can remove Nscaseinsensitivesearch and Nsanchoredsearch}*/    //specifies the range to find. We can use the options to determine the way the query is done. Start from the beginning or at the endNsrange nsstringrang= [str1 rangeofstring:@"NSString"Options:nscaseinsensitivesearch Range:nsmakerange (0, [str1 length])]; NSLog (@"Location=%lu,length=%lu", nsstringrang.location,nsstringrang.length); }//Interception of StringsvoidSubString () {//string InterceptionNSString *STR1 =@"Hello NSString"; //start at the end of the 5th character interceptNSString *substring = [str1 substringfromindex:5]; NSLog (@"%@", subString);//output NSStringNsrange rang = {0,5}; //specify a range to interceptNSString *subbyrang =[str1 Substringwithrange:rang]; NSLog (@"%@", Subbyrang);//Output Hello//intercept to the specified position starting from 0NSString *subtoposition= [str1 substringtoindex:5]; NSLog (@"%@", subtoposition);//Output Hello}//Creation of Stringsvoidcreatensstring () {//Creation of StringsNSString *STR1 =@"Hello NSString"; //static method to create a string,NSString *STR2 = [NSString stringWithFormat:@"nsstring%i",2]; //dynamic creation of a string, due to the dynamic creation of the counter will be +1 so we need to release it ourselves, STR3 initialization when there is no corresponding valueNSString *STR3 =[[NSString Alloc]init]; NSLog (@"%@", STR3);    [STR3 release]; }intMainintargcConst Char*argv[])        {@autoreleasepool {creatensstring ();        Basestringmeth ();        SubString ();        Nsstringsearch;    Mutablensstring (); }    return 0;}

Basic usage of nsstring and nsmutablensstring