The Excel CONCATENATE function joins together a series of supplied text strings or other values, into one combined text string.
The format of the function is:
where the text arguments are a set of one or more text strings or other values that you want to join together.
In current versions of Excel (Excel 2007 and later), you can supply up to 255 text arguments to the Concatenate function, but in Excel 2003, the function can only accept up to 30 text arguments.
Using the & Operator to Concatenate
Note that you can also use the & operator to concatenate in Excel.
This is described in the Excel String Concatenation page.The following spreadsheets show the Concatenate function, used to join together the strings in columns A  C of the example spreadsheet.
Formulas:
 
Results:

Note that, in the examples above:
Further information and examples of the Excel Concatenate function are provided on the Microsoft Office website.
One of the most common Concatenate problems encountered by Excel users is that the function result shows a date or time as a number, as shown below:
Formulas:
 
Results:

Dates and times in Excel are represented internally by numbers. It is simply the formatting of a cell that causes these numbers to be displayed as dates and times. Therefore, when an Excel date or time is supplied to the Concatenate function, the result displays the underlying numeric value.
This problem can be solved by using the Excel Text function to convert the date or time value into a text string. This is shown in the example spreadsheet below:
Formulas:
 
Results:
