oc笔记3（NSMutableString）

1.创建一个可变字符串

NSMutableString *str = [[NSMutableString alloc] initWithCapacity:10];

[str setString:@"1234"];

// 拼接字符串

[str appendString:@"567"];

[str appendFormat:@"age is %i and height is %.2f",27,1.55f];

// 替换字符串

NSRange range = [str rangeOfString:@"height"];  //找到height的range然后放到

 

下面就能替换

[str replaceCharactersInRange:range withString:@"no"]

 

// 插入字符串

[str insertString:@"abc" atIndex:2];

// 删除字符串

Range range = [str rangeOfString:@"age"];

[str deleteCharactersInRange:range];