第八讲：Objective-C基本数据结构之NSString

Sian · 发表于 2013-12-19 21:38:29

本帖最后由 Sian 于 2013-12-20 09:22 编辑

main.m

#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]){
@autoreleasepool {
char * s = "Hello C!"; //C语言字符串
NSString * str = @"Hello NSString!"; //OC字符串
NSString * srt1 = [[NSString alloc] initWithString:str]; //字符串传参
NSString * str2 = [[NSString alloc] initWithString:@"Hello NSString2!"];
NSString * str3 = [[NSString alloc] initWithUTF8String:"Hello C to OC!"];//用C的字符串创建OC的字符串对象
NSString * str4 = [[NSString alloc] initWithFormat:@"Hello %d%c!",2,'B'];//使用格式符，拼接字符串
NSString * str5 = [NSString stringWithUTF8String:"Hello C to OC! -Temp"];//对应临时字符串
NSString * str6 = [NSString stringWithFormat:@"Helllo %d%c! -Temp",2,'B'];//对应临时字符串
NSString * str7 = [NSString stringWithString:str];//对应临时字符串
NSLog(@"%s",s);
NSLog(@"%@",str);
NSLog(@"%@",srt1);
NSLog(@"%@",str2);
NSLog(@"%@",str3);
NSLog(@"%@",str4);
NSLog(@"%@",str5);
NSLog(@"%@",str6);
NSLog(@"%@",str7);
[str2 release];
[str3 release];
[str4 release];
//*****************************************************
NSString * str8 = @"Hello NSString8!";
BOOL ret = [str isEqualToString:str8]; //比较两个字符串是否相等
NSLog(@"%d",ret);
//*****************************************************
NSString * str9 = @"123";
NSString * str10 = @"456";
NSComparisonResult ret1 = [str9 compare:str10];//比较两个字符串大小
if(ret1 == NSOrderedAscending){
NSLog(@"str9 < str10!");
}else if(ret1 == NSOrderedDescending){
NSLog(@"str9 > str10!");
}else if(ret1 == NSOrderedSame){
NSLog(@"str9 = str10");
} //str9 < str10!
//*****************************************************
NSString * str11 = @"I am a so bad man.";
NSString * subStr = @"so";
NSRange range = [str11 rangeOfString:subStr];
NSLog(@"location:%lu length:%lu",range.location,range.length);//location:7 length:2
//*****************************************************
NSString * str12 = @"0123456789";
NSString * str13 = [str12 substringToIndex:6]; //从str中提取从头至第6个字符串(从0开始计算则不包含第6个的开区间)，生成新的字符串
NSString * str14 = [str12 substringFromIndex:6]; //从第6个字符开始提取，直至字符串尾，返回字符串地址
NSString * str15 = [str12 subStringWithRange:range1];
//NSString * str16 = [str12 substringWithRange:NSMakeRange(4, 4)];
NSLog(@"%@",str12);
NSLog(@"%@",str13);
NSLog(@"%@",str14);
NSLog(@"%@",str15);
//NSLog(@"%@",str16);
}
return 0;
}

复制代码

Sian · 发表于 2013-12-22 21:15:52

值得注意的是：比较两个字符串的大小"compare"方法不是我们传统意义上的数值加减，数字与字符同样可以进行比较。我测试了一下，123<456这很正常，但1234<456这个要做何解释？456＝456，4567>456，4552<456等等，一起研究一下吧。

Sian · 发表于 2014-1-8 19:42:09

//
// main.m
// NSString
//
// Created by yusian on 14-1-6.
// Copyright (c) 2014年 yusian. All rights reserved.
//
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[])
{
@autoreleasepool{
NSString * str = @"Hello str!";
NSLog(@"%@",str);
NSString * str1 = [[NSString alloc] initWithString:@"Hello OC!"];
NSLog(@"%@",str1);
[str1 release];
NSString * str2 = [[NSString alloc] initWithFormat:@"Hello %d%c!",2,'B'];
NSLog(@"%@",str2);
[str2 release];
NSString * str3 = [[NSString alloc] initWithString:str];
NSLog(@"%@",str3);
[str3 release];
NSString * str4 = [NSString stringWithFormat:@"Hello Temp %d%c",2,'B'];
NSLog(@"%@",str4);
NSString * str5 = [NSString stringWithString:str];
NSLog(@"%@",str5);
NSString * str6 = [NSString stringWithUTF8String:"Hello Temp str"];
NSLog(@"%@",str6);
//****************************************************
NSString * str7 = @"Hello Temp str";
BOOL ret = [str7 isEqualToString:str6];
NSLog(@"%d",ret);
//****************************************************
NSString * str8 = @"123";
NSString * str9 = @"234";
NSComparisonResult ret1 = [str8 compare:str9];
if (ret1 == NSOrderedSame)
NSLog(@"str8 = str9");
else if (ret1 == NSOrderedAscending)
NSLog(@"str8 < str9");
else if (ret1 == NSOrderedDescending)
NSLog(@"str8 > str9");
//****************************************************
NSString * str10 = @"This is a NSString test!";
NSString * str11 = @"st";
NSRange range = [str10 rangeOfString:str11];
NSLog(@"%ld,%ld",range.length,range.location);
//****************************************************
NSString * str12 = @"abcdefghijklmnopqrstuvwxyz";
NSString * str13 = [str12 substringFromIndex:23];
NSLog(@"%@",str13);
NSString * str14 = [str12 substringToIndex:7];
NSLog(@"%@",str14);
NSString * str15 = [str12 substringWithRange:NSMakeRange(7, 7)];
NSLog(@"%@",str15);
}
return 0;
}

复制代码

Sian · 发表于 2014-1-8 19:43:02

以下结果运行如下：

2014-01-08 19:41:30.861 NSString[1881:303] Hello str!
2014-01-08 19:41:30.863 NSString[1881:303] Hello OC!
2014-01-08 19:41:30.863 NSString[1881:303] Hello 2B!
2014-01-08 19:41:30.863 NSString[1881:303] Hello str!
2014-01-08 19:41:30.863 NSString[1881:303] Hello Temp 2B
2014-01-08 19:41:30.864 NSString[1881:303] Hello str!
2014-01-08 19:41:30.864 NSString[1881:303] Hello Temp str
2014-01-08 19:41:30.864 NSString[1881:303] 1
2014-01-08 19:41:30.865 NSString[1881:303] str8 < str9
2014-01-08 19:41:30.865 NSString[1881:303] 2,21
2014-01-08 19:41:30.865 NSString[1881:303] xyz
2014-01-08 19:41:30.866 NSString[1881:303] abcdefg
2014-01-08 19:41:30.866 NSString[1881:303] hijklmn
Program ended with exit code: 0

复制代码

帐号		自动登录	找回密码
密码			立即注册