IOS学习笔记十六(NSString和NSMutableString)

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
  
 

文章来源: chenyu.blog.csdn.net，作者：chen.yu，版权归原作者所有，如需转载，请联系作者。

原文链接：chenyu.blog.csdn.net/article/details/81008266