NSArray  *arr1 = @[@"1",@"3",@"7",@"6",@"4",];

NSArray  *arr2 = @[@"2",@"4",@"7",@"6",@"9"];

//数组合并

NSArray*arr = [arr1arrayByAddingObjectsFromArray:arr2];

//使用NSSet集合去重，NSSet是集合的意思

NSSet*set = NSSetsetWithArray:arr];

//数组排序

NSArray*array = [setsortedArrayUsingDescriptors:@[[NSSortDescriptorsortDescriptorWithKey:nilascending:YES]]];

第二种方式

NSMutableArray*array2 =  [NSMutableArray   array];

for (int i =0; i<arr1.count; i++){

for (int j = 0;j<arr2.count.count; j++){

if(arr1[i]==arr2[j]){

[array2 addObject:arr1[i]];

}}}

NSArray*paixu = [array2sortedArrayUsingDescriptors:@[[NSSortDescriptorsortDescriptorWithKey:nilascending:YES]]];

NSLog(@"array2 =%@",paixu);