第九讲：Objective-C基本数据结构之NSMutableString
main.m#import <Foundation/Foundation.h>
int main(int argc, const char * argv[])
{
@autoreleasepool{
//NSMutableString * str = @"Hello World!";//该方法不能用来创建一个可变字符串！！
NSMutableString * str = [ initWithString:@"Hello"];
NSMutableString * str1 = [ init];
;
;
NSLog(@"%@",str1);
//****************************************可变字符串之增
;//追加
;//格式化增加
;//在第4个字符处插入XXXX
atIndex:7];//格式化插入
NSLog(@"%@",str1);
//****************************************可变字符串之删
;//从第三个开始删除5个字符
NSLog(@"%@",str1);
NSSMutableString * str = @"Hello World!"; //不能用该方式来初始化（或赋值）一个可变字符串
错误提示：incompatible pointer types initializing 'NSMutableString *' with an expression of type 'NSString *'
翻译一下：不兼容的指针类型"NSString"初始化了一类型为"NSMutableString"的指针;（大概如此）
但实际上会编译通过并且输出：
2014-01-08 19:45:21.064 NSMutableString Hello World!
Program ended with exit code: 0
XCode正式代码：
//
//main.m
//NSMutableString
//
//Created by yusian on 14-1-8.
//Copyright (c) 2014年 yusian. All rights reserved.
//
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[])
{
@autoreleasepool {
NSMutableString * str = [ initWithString:@"Hello str!"];
NSLog(@"%@",str);
;
NSMutableString * str1 = [ init];
;
;
NSLog(@"%@",str1);
;
NSMutableString * str2 = [ init];
;
;
;
NSLog(@"%@",str2);
;
NSLog(@"%@",str2);
;
NSLog(@"%@",str2);
;
}
return 0;
}
输出结果：
2014-01-08 20:28:39.507 NSMutableString Hello str!
2014-01-08 20:28:39.508 NSMutableString Hello World!
2014-01-08 20:28:39.509 NSMutableString NSString!
2014-01-08 20:28:39.509 NSMutableString NSMutableString!
2014-01-08 20:28:39.509 NSMutableString NSString!
Program ended with exit code: 0
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