02-NSString的连接、使用和打印
//5、创建格式化字符串:占位符（由一个%加一个字符组成）??? int i = 1;
? ? int j = 2;
? ? NSString *astring = [[NSString alloc]?initWithString:[NSString?stringWithFormat:@"%d.This is %i string!",i,j]];
? ? NSLog(@"astring:%@",astring);
? ? [astring release];

-----从文件读取字符串-----
??? NSString *path = @"astring.text";
? ? NSString *astring = [[NSString alloc]?initWithContentsOfFile:path];
? ? NSLog(@"astring:%@",astring);
? ? [astring release];

-----写字符串到文件----????
??? NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
? ? NSLog(@"astring:%@",astring);
? ? NSString *path = @"astring.text";? ?
? ? [astring?writeToFile: path atomically: YES];
? ? [astring release];???
-----比较两个字符串-----
//1、用C比较:strcmp函数
??? char string1[] = "string!";
? ? char string2[] = "string!";
? ? if(strcmp(string1, string2) = = 0)
? ? {
? ?? ???NSLog(@"1");
? ? }
?//2、isEqualToString方法? ?
? ? NSString *astring01 = @"This is a String!";
? ? NSString *astring02 = @"This is a String!";
? ? BOOL result = [astring01?isEqualToString:astring02];
? ? NSLog(@"result:%d",result);
//3、compare方法(comparer返回的三种值：NSOrderedSame，NSOrderedAscending，NSOrderedDescending)? ?
? ? NSString *astring01 = @"This is a String!";
? ? NSString *astring02 = @"This is a String!";? ?
? ? BOOL result = [astring01?compare:astring02] = =?NSOrderedSame;???//NSOrderedSame 判断两者是否相同
??? NSLog(@"result:%d",result);???

??? NSString *astring01 = @"This is a String!";
? ? NSString *astring02 = @"this is a String!";
? ? BOOL result = [astring01?compare:astring02] = =?NSOrderedAscending;? ?
? ? NSLog(@"result:%d",result);
? ? //NSOrderedAscending 判断两对象值的大小(按字母顺序进行比较，astring02大于astring01为真)

? ? NSString *astring01 = @"this is a String!";
? ? NSString *astring02 = @"This is a String!";
? ? BOOL result = [astring01?compare:astring02] = =?NSOrderedDescending;? ?
? ? NSLog(@"result:%d",result);? ???
? ? //NSOrderedDescending 判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)
?//4、不考虑大小写比较字符串1
? ? NSString *astring01 = @"this is a String!";
? ? NSString *astring02 = @"This is a String!";
? ? BOOL result = [astring01?caseInsensitiveCompare:astring02] = = NSOrderedSame;? ?
? ? NSLog(@"result:%d",result);? ???
? ? //NSOrderedDescending判断两对象值的大小(按字母顺序进行比较，astring02小于astring01为真)
//5、不考虑大小写比较字符串2
? ? NSString *astring01 = @"this is a String!";
? ? NSString *astring02 = @"This is a String!";
? ? BOOL result = [astring01 compare:astring02
? ?? ?? ?? ?? ?? ?? ?? ?? ? options:NSCaseInsensitiveSearch | NSNumericSearch] = = NSOrderedSame;? ?
? ? NSLog(@"result:%d",result);?????
?? ?//NSCaseInsensitiveSearch:不区分大小写比较 NSLiteralSearch:进行完全比较，区分大小写 NSNumericSearch:比较字符串的字符个数，而不是字符值。

? ? NSLog(@"%@ ",order);//打印字典

? ??NSLog(@"%@ ",imageUrlString);