课堂笔记08

来源：互联网发布：图书数据哪个网站多编辑：程序博客网时间：2024/06/08 15:27

NSMutableString //可变字符串

     可变字符串 ‘NSMutableString’ 是继承于不可变字符串

   NSMutableString *ms = @"hello";//默认不可变   //5种初始化方法   NSMutableString *mst0 = [NSMutableString stringWithString:@"hello world"];   NSMutableString *mst1 = [NSMutableString stringWithFormat:@"hello"];   NSMutableString *mst2 = [NSMutableString stringWithContentsOfFile:@"" encoding:4 error:nil];   NSMutableString *mst3 = [NSMutableString stringWithContentsOfURL:[NSURL URLWithString:@""] encoding:4 error:nil];   //可变字符串独特初始化方法，初始化一个空间为100的可变字符串   NSMutableString  *mst4 = [[NSMutableString alloc] initWithCapacity:100];

    //C语言字符数组转换成 OC 的字符串    [[NSString alloc] initWithCharacters:<#(const unichar *)#> length:<#(NSUInteger)#>]

//替换  NSMutableString *st3 = [NSMutableString stringWithString:@"ssb"];  NSRange range = [st3 rangeOfString:@"sb"];  [st3 replaceCharactersInRange:range withString:@"**"];  NSLog(@"%@",st3);

//增加,在指定位置插入一段字符串  [st3 insertString:@",你是sb么？" atIndex:st3.length];  NSLog(@"%@",st3);//末尾增加   [st3 appendString:@",你是sb么？"];//添加一个   [st3 appendFormat:@"%@%@",@"sX",@"JJ fly"];//拼接多个    NSLog(@"%@",st3);

//删除  [st3 deleteCharactersInRange:NSMakeRange(0, 3)];  NSLog(@"%@",st3);

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