1、NSString和NSMutableString
NSString是不变字符串类，有点像java里面的String,NSMutableString是可变字符串类，有点类似java里面的StringBuffer
2、测试demo
int main(int argc, char * argv[]) { @autoreleasepool { unichar data[6] = {97, 98, 100, 101, 102, 103}; NSString *str = [[NSString alloc] initWithCharacters:data length:6]; NSLog(@"str is %@", str); char *cstr = "chenyu"; NSString *str2 = [NSString stringWithUTF8String:cstr]; NSLog(@"str2 is %@", str2); NSString *str3 = @"chenyu"; NSString *name = @"陈喻"; str3 = [str3 stringByAppendingString:@"chenyu"]; NSLog(@"str3 is %@", str3); const char *cstr1 = [str3 UTF8String]; NSLog(@"cstr1 is %s", cstr1); str3 = [str3 stringByAppendingFormat:@"hello %@ hello", name]; NSLog(@"str3 is %@", str3); NSLog(@"str3 length is %lu", [str3 length]); NSString *s1 = [str3 substringToIndex:10]; NSLog(@"s1 is %@", s1); NSString *s2 = [str3 substringFromIndex:5]; NSLog(@"s2 is %@", s2); NSString *s3 = [str3 substringWithRange:NSMakeRange(5,10)]; NSLog(@"s3 is %@", s3); NSRange pos = [str3 rangeOfString:@"陈喻"]; NSLog(@"陈喻在str3中开始的位置：%ld,长度为%ld", pos.location, pos.length); str3 = [str3 uppercaseString]; NSLog(@"str3 is %@", str3); NSMutableString *tstr = [NSMutableString stringWithString:@"hello"]; [tstr appendString:@"chenyu"]; NSLog(@"tstr is %@", tstr); [tstr appendFormat:@"hello word %@", @"chengongyu"]; NSLog(@"tstr is %@", tstr); [tstr insertString:@"hello" atIndex:6]; NSLog(@"tstr is %@", tstr); [tstr deleteCharactersInRange:NSMakeRange(6, 9)]; NSLog(@"tstr is %@", tstr); [tstr replaceCharactersInRange:NSMakeRange(3, 6) withString:@"objectobject"]; NSLog(@"tstr is %@", tstr); } }
3、运行结果
str is abdefg str2 is chenyu str3 is chenyuchenyu cstr1 is chenyuchenyu str3 is chenyuchenyuhello 陈喻 hello str3 length is 26 s1 is chenyuchen s2 is uchenyuhello 陈喻 hello s3 is uchenyuhel 陈喻在str3中开始的位置：18,长度为2 str3 is CHENYUCHENYUHELLO 陈喻 HELLO tstr is hellochenyu tstr is hellochenyuhello word chengongyu tstr is hellochellohenyuhello word chengongyu tstr is hellocuhello word chengongyu tstr is helobjectobjectllo word chengongyu
