Excel to find Repeated Records countif

Solution1:
Select columns -- filter -- Advanced filtering -- select "do not repeat records" on the hook -- select "copy the filtering result to another location" -- select the copied position, which is assumed to be the right column
Then compare them with the naked eye.
Solution2:
1. Insert the formula: = countif (A: A, A2) into a cell on the right of the column (assuming column)
A: A -- Range (for example, a: C indicates that the data from column A to column C needs to be compared)
A2 -- Criteria compares the data in cells.
2. Place the mouse in the lower right corner of the grid and pull down (that is, copy ). (If you press Ctrl at the same time, it will copy and auto-increment)
In this way, the number of data duplicates is displayed.