iOS简单排序--字母排序、NSDictionary排序

// 数组用系统方法compare做字母的简单排序

NSArray *oldArray = @[@"bac",@"bzd",@"azc",@"azz"];

NSArray *newArray = [oldArray sortedArrayUsingSelector:@selector(compare:)];

NSLog(@"new array = %@",newArray);

// 因为NSDictionary排序

NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];

[dict setObject:@"1" forKey:@"key1"];

[dict setObject:@"2" forKey:@"key2"];

[dict setObject:@"3" forKey:@"key3"];

[dict setObject:@"4" forKey:@"key4"];

for (NSString *str in [dict allKeys]) {

NSLog(@"key == %@",str);

}

NSArray *keys = [dict allKeys];

NSArray *sortedArray = [keys sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2){

return [obj1 compare:obj2 options:NSNumericSearch];

}];

for (NSString *categoryId in sortedArray) {

NSLog(@"[dict objectForKey:categoryId] === %@",[dict objectForKey:categoryId]);

}