The For Each Loop allows you to easily traverse all elements in an array to access all stored values.
Here is how a foreach loop looks like:
For Each item As String In list
'statements
Next
As you can see, it is significantly simpler than the standard For Next Loop and therefore is very often preferred by developers because it saves writing when you need to go through all the elements of a given collection.
Let's consider a very simple example of using the For Each Loop
Public Sub Example1()
Dim websites As String() = New String(4) {"Google", "YouTube", "Facebook", "Baidu", "Yahoo"}
For Each site As String In websites
Console.WriteLine(site)
Next
End Sub
In the above example, an array of website names (strings) is created and iterate over elements, and print on the console.
Let's run the above code and it will print the following output on the console window.
Google
YouTube
Facebook
Baidu
Yahoo!
Here is another example that is a little bit more complicated. A For Each Loop can also be used to traverse all the elements of a Dictionary that contains key-value pairs.
The data types of the key and value must be specified as a comma-separated pair within <> (angled brackets) in the declaration.
Public Sub Example2()
Dim numberNames As Dictionary(Of Integer, String) = New Dictionary(Of Integer, String)()
numberNames.Add(1, "One")
numberNames.Add(2, "Two")
numberNames.Add(3, "Three")
For Each item As KeyValuePair(Of Integer, String) In numberNames
Console.WriteLine("Key: {0}, Value: {1}", item.Key, item.Value)
Next
End Sub
Let's run the above example and you will see the iterator display the dictionary's key-value pair.
Key: 1, Value: One
Key: 2, Value: Two
Key: 3, Value: Three