title: how to assign value to users in a data.frame based on user ID records from another data.frame
body: <p>I have read excel file in R, where sheet1 has 51500 rows and 5 column and sheet 2 has user ID of buyers (only one column). <strong>Objective</strong>: Aim to extract the user in sheet_1 whose User Id are occurred in sheet 2.
  Here is the two example input files and desired output: </p>
  
  <pre><code>df &lt;- data.frame(User.ID=c(12: 17), Group="Test", Spend=c(15:20), Purchase=c(5:10))
  
      df
    User.ID Group Spend Purchase
  1      12  Test    15        5
  2      13  Test    16        6
  3      14  Test    17        7
  4      15  Test    18        8
  5      16  Test    19        9
  6      17  Test    20       10
  
   hash.ID &lt;- data.frame(User.ID= c(13:16))
  
    User.ID
  1      13
  2      14
  3      15
  4      16
  
  desired output : 
  
    User.ID Group Spend Purchase     Redem_Status
  1      12  Test    15        5    Test_NonRedeemer
  2      13  Test    16        6    Test_Redeemer
  3      14  Test    17        7    Test_Redeemer
  4      15  Test    18        8    Test_Redeemer
  5      16  Test    19        9    Test_Redeemer
  6      17  Test    20       10    Test_NonRedeemer
  </code></pre>
  
  <p>based on above example, we can see that if user Id from df is existed in hash.ID table, then we add new column and label it as Test_Redeemer, otherwise label it as Test_NonRedeemer. Is there any straightforward approach that can do this task ? Thanks a lot !!</p>