What is the use of Concatenation Operator in Excel?

The concatenation operator is a binary operator, whose syntax is shown in the general diagram for an SQL Expression. You can use the concatenation operator ( || ) to concatenate two expressions that evaluate to character data types or to numeric data types.

Private Sub Constant_demo_Click()
   Dim a as Integer : a = 5
   Dim b as Integer : b = 10
   Dim c as Integer

   c = a + b  
   msgbox ("Concatenated value:1 is " &c) 'Numeric addition 
   c = a & b 
   msgbox ("Concatenated value:2 is " &c) 'Concatenate two numbers 
End Sub