文档介绍：iOS开发常用的代码%c一个单一的字符%d一个十进制整数%i一个整数%e,%f,%g一个浮点数%o一个八进制数%s一个字符串%x一个十六进制数%p一个指针%n一个等于读取字符数量的整数%u一个无符号整数%[]一个字符集%%一个精度符号//一、NSString/*----------------创建字符串的方法----------------*/1、创建常量字符串。NSString*astring=@"ThisisaString!";2、创建空字符串,给予赋值。NSString*astring=[[NSStringalloc]init];astring=@"ThisisaString!";NSLog(@"astring:%@",astring);[astringrelease];3、在以上方法中,提升速度:initWithString方法NSString*astring=[[NSStringalloc]initWithString:@"ThisisaString!"];NSLog(@"astring:%@",astring);[astringrelease];4、用标准c创建字符串:initWithCString方法char*Cstring="ThisisaString!";NSString*astring=[[NSStringalloc]initWithCString:Cstring];NSLog(@"astring:%@",astring);[astringrelease];5、创建格式化字符串:占位符(由一个%加一个字符组成)inti=1;intj=2;NSString*astring=[[NSStringalloc]initWithString:[NSStringstringWithFormat:@"%%istring!",i,j]];NSLog(@"astring:%@",astring);[astringrelease];6、创建临时字符串NSString*astring;astring=[NSStringstringWithCString:"Thisisatemporarystring"];NSLog(@"astring:%@",astring);/*----------------从文件读取字符串:initWithContentsOfFile方法----------------*/NSString*path=@"";NSString*astring=[[NSStringalloc]initWithContentsOfFile:path];NSLog(@"astring:%@",astring);[astringrelease];/*----------------写字符串到文件:writeToFile方法----------------*/NSString*astring=[[NSStringalloc]initWithString:@"ThisisaString!"];NSLog(@"astring:%@",astring);NSString*path=@"";[astringwriteToFile:pathatomically:YES];[astringrelease];/*----------------比较两个字符串----------------*/用C比较:strcmp函数charstring1[]="string!";charstring2[]="string!";if(strcmp(string1,string2)==0){NSLog(@"1");}isEqualToString方法NSString*astring01=@"ThisisaString!";NSString*astring02=@"ThisisaString!";BOOLresult=[astring01isEqualToString:astring02];NSLog(@"result:%d",result);parer返回的三种值)NSString*astring01=@"ThisisaString!";NSString*astring02=@"ThisisaString!";BOOLresult=[pare:astring02]==NSOrderedSame;NSLog(@"result:%d",result);NSOrderedSame判断两者内容是否相同NSString*astring01=@"ThisisaString!";NSString*astring02=@"thisisaString!";BOOLresult=[pare:astring02]==NSO