Shorthand for conditional statements

Question

I am looking for a way to write something like this:

if (product.Category.PCATID != 10 && product.Category.PCATID != 11 && product.Category.PCATID != 16) {   }

In a shorthand way like below, which does not work of course:

if (product.Category.PCATID != 10 | 11 | 16) {   }

So is there shorthand way at all to do something similar ?

It's been answered in this question as well: http://stackoverflow.com/questions/9033/hidden-features-of-c/33384#33384 — Patrick, Sep 22 '11 at 13:05
@LaserBeak: Your latest edit changes your question **COMPLETELY**! This doesn't even compile. — Daniel Hilgarth, Sep 22 '11 at 13:16
@LaserBeak: It is very bad practice to change your question substantially after answers have been posted. — Daniel Hilgarth, Sep 22 '11 at 16:25

score 6 · Answer 1 · answered Sep 22 '11 at 12:50

6

Yes - you should use a set:

private static readonly HashSet<int> FooCategoryIds
    = new HashSet<int> { 10, 11, 16 };

...

if (!FooCategoryIds.Contains(product.Category.PCATID))
{
}

You can use a list or an array or basically any collection, of course - and for small sets of IDs it won't matter which you use... but I would personally use a HashSet to show that I really am only interested in the "set-ness", not the ordering.

answered Sep 22 '11 at 12:50

Jon Skeet

1,421,763
867
9,128
9,194

For more info and uses of the HashSet, look here. http://johnnycoder.com/blog/2009/12/22/c-hashsett/ – Jeff Reddy Sep 22 '11 at 12:53

score 5 · Accepted Answer · answered Sep 22 '11 at 13:06

5

You could use an extension method:

    public static bool In<T>(this T source, params T[] list)
    {
        return list.Contains(source);
    }

And call it like:

  if (!product.Category.PCATID.In(10, 11, 16)) {  }

answered Sep 22 '11 at 13:06

Hans Keﬆing

38,117
9
79
111

yas4891 · Answer 3 · 2011-09-22T12:52:26.283

3

not exactly a shortcut, but maybe the right thing for you.

var list = new List<int> { 10, 11, 16 };
if(!list.Contains(product.Category.PCATID))
{
  // do something
}

edited Sep 22 '11 at 12:52

answered Sep 22 '11 at 12:50

yas4891

4,774
3
34
55

score 2 · Answer 4 · answered Sep 22 '11 at 12:58

Well... I think a shorthand version would be if(true), because if PCATID == 10, it is != 11 and != 16, so the whole expression is true.
The same goes for PCATID == 11 and for PCATID == 16.
And for any other number all three conditions are true.
==> You expression will always be true.

The other answers are only valid, if you really meant this:

if (product.Category.PCATID != 10 && 
    product.Category.PCATID != 11 && 
    product.Category.PCATID != 16) {   }

score 1 · Answer 5 · answered Sep 22 '11 at 12:52

1

You could do something like that:

List<int> PCATIDCorrectValues = new List<int> {10, 11, 16};

if (!PCATIDCorrectValues.Contains(product.Category.PCATID)) {
    // Blah blah
}

answered Sep 22 '11 at 12:52

Otiel

18,404
16
78
126

score 1 · Answer 6 · answered Sep 22 '11 at 14:53

1

if (!new int[] { 10, 11, 16 }.Contains(product.Category.PCATID))
{
}

Add using System.Linq to the top of your class or .Contains generates a compile error.

answered Sep 22 '11 at 14:53

Nope

22,147
7
47
72

score 0 · Answer 7 · answered Feb 19 '15 at 06:55

Make it simple with switch:

switch(product.Category.PCATID) {
    case 10:
    case 11:
    case 16: {
        // Do nothing here
        break;
    }
    default: {
        // Do your stuff here if !=10, !=11, and !=16
        //    free as you like
    }
}

Shorthand for conditional statements

7 Answers7