problem with comparing arraylists

hello there! I've got two arraylists named a1 and a2. I need to check if these two arraylists have the same contents. All I can think of is this------

Code:

---

for (int j = 0; j < a1.Count;j++ )
            {
                for (int i = 0; i < a2.Count; i++)
                {
                    if
                    ((a1[j])==(a2[i]))
                    {
                          return something................}
}
}

---

please help me find a solution
thanks in advance
lamiajoyee

Does the order of elements matter?

yes the order matters.and one more thing,the lists dont have to be the same,i need to check if certain elements are there in the list

First, don't use ArrayList if all your objects in the list are of equivalent type. Use List<T> instead; see the C# generics tutorial (link.

Second, to test for equality (for example):

Code:

---

for(int i = 0; i < a1.Count; i++)
{
    //If any two elements aren't equal, the whole array isn't
    if( a1[i] != a2[i] )
        return false;
}

//Otherwise all the elements must have been equal
return true;

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Similarly, suppose you had a different restriction like ("I require elements 6, 8, and 9 in a1 to be equal to elements 3, 7, and 12 in a2"). Then do:

Code:

---

public static bool compareRestriction(List<T> a1, List<T>a2)
{
    return compareRestriction(a1, a2, new Tuple<int, int>[] {
        new Tuple<int, int>(6,3),
        new Tuple<int, int>(8,7),
        new Tuple<int, int>(9,12) };
}

public static bool compareRestriction(List<T> a1, List<T> a2, Tuple<int, int>[] matchesRequired)
{
    for(int i = 0; i < matches.Length; i++)
    {
        if( !(a1[matches[i].Item1].Equals(a2[matches[i].Item2])) )
            return false;
    }
   
    return true;
}

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