distinguishes/case-insensitive comparisons, finds the position of a string in another string, and whether the beginning of the string includes another string Hasprefix

NSString *str;//using stringWithFormat to generate a formatted stringstr = [NSString stringWithFormat:@"This is %@","John"]; NSLog (@"STR--->%@", str);//string lengths length;NSLog (@"The length of this string is%@", [str length]);//string comparison isequaltostring, return no (false), isequaltostring case-sensitiveBOOL isequal = [str isequaltostring:@"This is John"]; //The string sequence is compare than the column and returns the result Nscomparisonresult//type enum _nscomparisonresult{//nsorderedascending =-1,//Nsorderedsame,//nsordereddescending// }intresult = [@"BOOL"Compare@"Cool"]; NSLog (@"The result is%d", result); //Compare comparison rules options//Nsliteralsearch Case-sensitive (full comparison)//Nscaseinsensitivesearch Case insensitive//Nsnumericsearch compares only the number of strings, not the literal value of a stringintRESULT1 = [@"This is John"Compare@"This is John"Options:nscaseinsensitivesearch |Nsnumericsearch]; NSLog (@"The result is%d", RESULT1); //whether the beginning of the string includes another string hasprefix, returns the result Yes (true)BOOL Ishas = [str hasprefix:@" This"];//whether the end of the string includes another string hassuffix, returns the result Yes (true)BOOL Ishas = [str hassuffix:@"John"]; //find the position of a string in another stringNsrange range = [str rangeofstring:@" is"Options:nscaseinsensitivesearch]; NSLog (@"The location of the string named ' str ' of ' was ' is @d", range.location);

distinguishes/case-insensitive comparisons, finds the position of a string in another string, and whether the beginning of the string includes another string Hasprefix