How to compare two array

a!localVariables(
  local!checkExcelItemsInRefTable: a!forEach(
    items: ri!excelArray,
    expression: contains(
      {
        ri!refTablearray
      },
      fv!item
    )
  ),
  /*Match each index of array to return a boolean array if match was found or not*/
  local!notFoundIndexes: wherecontains(
    false,
    local!checkExcelItemsInRefTable
  ),
  /*Indexes from excel array where the match wasn't found*/
  concat(
    joinarray(
      index(
        ri!excelArray,
        {
          local!notFoundIndexes
        },
        {}
      ),
      ", "
    ),
    " not found in reference table"
  )/*Returning the message with the values not found in reference table*/
  
)

Use a code like this to compare arrays and get the following result.

Hope it helps!

Regards,

Kunal

a!localVariables(
  local!referenceTableData: {
    "india",
    "usa",
    "Australia",
    "uk"
  },
  local!excelData: {
    "india",
    "usa",
    "Australi",
    "Iran"
  },
  local!notPresentList: a!forEach(
    items: local!excelData,
    expression: if(
      contains(
        local!referenceTableData,
        fv!item
      ),
      {},
      fv!item
    )
  ),
  concat(
    a!forEach(
      items: local!notPresentList,
      expression: if(
        fv!isLast,
        fv!item,
        concat(
          fv!item,
          ","
        )
      )
    ),
    " is not present in data"
  )
)

Hi Nikkheel,

You can use simple built in Appian function. 

difference({"india", "usa", "Australi"}, {"india", "usa", "Australia","uk"})

Thank you its working