在目标C中连接nsstring

NSMutableString* someString = [NSMutableString stringWithString: @"Hello"];
[someString appendString: @", world!"];

NSString *firstString = @"FirstString";
NSString *secondString = @"SecondString";
NSString *concatinatedString = [firstString stringByAppendingString:secondString];
// Note that concatinatedString is autoreleased, 
// so if you may want to [concaticatedString retain] it.

NSMutableString *firstString = [NSMutableString stringWithString:@"FirstString"];
NSString *secondString = @"SecondString";
[firstString appendString:secondString];
// Note that firstString is autoreleased, 
// so if you may want to [firstString retain] it.