按NSDictionary的key来对其进行排序：
先将dict的allkeys赋给一个数组，然后通过sortedArrayUsingComparator:方法对数组排序，然后遍历数组取字典对应key的值就ok
NSArray *keys = [dict allKeys];
NSArray *sortedArray = [keys sortedArrayUsingComparator:^NSComparisonResult(idobj1, id obj2) {
return [obj1 compare:obj2 options:NSNumericSearch];
}];
for (NSString *categoryId in sortedArray) {
⋯⋯
NSLog(@"[dict objectForKey:categoryId] === %@",[dictobjectForKey:categoryId]);
}
优化结果:
//对字典中的值进行排序
keys = [dict3keysSortedByValueUsingSelector:@selector(compare:)];
for(NSString*sinkeys)
{
NSLog(@"%@ = %@", s, dict3[s]);
}
方法二：
NSString *filePath = [[NSBundle mainBundle]pathForResource:@"students" ofType:@"plist"];
NSDictionary *stuDic = [NSDictionary dictionaryWithContentsOfFile:filePath];
self.studentIndexArray = [NSMutableArray arrayWithCapacity:1];
NSArray *arr = [[stuDic allKeys] sortedArrayUsingSelector:@selector(compare:)];
字典遍历:
//遍历
NSEnumerator*e = [dict3objectEnumerator];//枚举器值遍历
while(str = [enextObject])
{
NSLog(@"%@", str);
}
e = [dict3keyEnumerator];//枚举器关键字遍历
while(str = [enextObject])
{
NSLog(@"%@", str);
}
for(NSString*keyindict3)//快速遍历
{
NSLog(@"%@=%@", key, dict3[key]);
}
//字典的文件读写方法
[dict3writeToFile:@"/Users/#####/Desktop/dict.plist"atomically:YES];
NSDictionary*dict6 = [NSDictionarydictionaryWithContentsOfFile:@"/Users/######/Desktop/dict.plist"];
NSLog(@"%@", dict6);