How to search a List of array?

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Hello;
I have this List

VB

Dim Lst as New List(of Array)
Lst.Add({12,100,58})
Lst.Add({25,47,23})
Lst.Add({15,19,203})

Can I search this list for an exact and get the index without using a loop.
For example search for 47, he will get found Lst(1)

Posted 12-Jan-14 7:03am

Member 9451601

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2 solutions

Solution 1

Try this:

VB

Dim Lst As New List(Of Array)
Lst.Add({12, 100, 58})
Lst.Add({25, 47, 23})
Lst.Add({15, 19, 203})
Dim arrIndex As Integer = -1
Dim i As Integer = 0
For Each arr As Integer() In Lst
    If arr.Contains(47) Then
        arrIndex = i
        Exit For
    End If
    i += 1
Next
Console.WriteLine(arrIndex)

This will print 1. If you search for an integer that doesn't exist, it will print -1

How this works: you iterate over each array in the List, and if that array contains 47, the arrIndex variable will be set to the index of the array in the list.

Posted 12-Jan-14 7:10am

Thomas Daniels

v2

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Meshack Musundi · Accepted Answer · 2014-01-12T09:52:00

Solution 2

VB.NET

Dim Lst As New List(Of Integer())
Lst.Add({12, 100, 58})
Lst.Add({25, 47, 23})
Lst.Add({15, 19, 203})

Dim index = Lst.FindIndex(Function(n) n.Contains(47))

Note that the List is a List(of Integer()). This enables you to call the Contains() method in the Lambda expression that is the predicate of the FindNext() method.

Posted 12-Jan-14 9:52am

Meshack Musundi

Comments

Member 9451601 15-Jan-14 14:15pm

I noticed you wrote List(of Integer()) Instead of List(of Array())
But you added an array and not an integer
So can you explain

Meshack Musundi 15-Jan-14 14:48pm

The arrays you are adding to your list are arrays of Integers so it's a List(Of Integer()) (List of Integer arrays). Note the opening and closing brace after Of Integer.