第四天 NSMutableString

NSString (不可变字符串)

NSMutableString（可变字符串）

NSMutableString 是继承了NSString的方法

//初始化可变参数字符串

   NSMutableString *muString=[NSMutableString alloc]initWithCapacity:20;

//静态方法
        NSMutableString *muString2=[NSMutableString stringWithCapacity:20];

//可变字符串的添加

- (void)insertString:(NSString *)aString atIndex:(NSUInteger)loc;

//删除字符串
- (void)deleteCharactersInRange:(NSRange)range;

 NSMutableString *muString2=[[NSMutableString alloc]initWithCapacity:20];
       
        NSRange r=NSMakeRange(2, 3);
        [muString2 deleteCharactersInRange:r];
        NSLog(@"%@",muString2);

//追加
- (void)appendString:(NSString *)aString;

eg:

NSMutableString *muString2=[NSMutableString stringWithCapacity:20];
        [muString2 appendString:@"xiao luo"];
        [muString2 appendString:@"20"];
        NSLog(@"%@",muString2);

//在某个位子添加
- (void)appendFormat:(NSString *)format, ... NS_FORMAT_FUNCTION(1,2);

eg:

NSString *s=@"test";
        NSMutableString *muString3=[NSMutableString stringWithString:@"HELLo World"];
        [muString3 insertString:s atIndex:3];
        NSLog(@"%@",muString3);

//替换
- (void)setString:(NSString *)aString;

eg:

NSMutableString *muString4=[NSMutableString stringWithString:@"HELLo"];
        [muString4 setString:@"World"];
        NSLog(@"%@",muString4);