Can list contains duplicates C#?

Place all items in a set and if the count of the set is different from the count of the list then there is a duplicate. Should be more efficient than Distinct as there is no need to go through all the list. Something along these lines is relatively simple and will provide you with a count of duplicates.

How do you check if there are duplicates in a list C#?

“Check if the is duplicate in list C#” Code Answer

1. var list = new List();
2. ​
3. // Fill the list.
4. ​
5. if(list. Count != list. Distinct(). Count())
6. {
7. // Duplicates exist.
8. }

How do I find duplicate records in Linq?

To find the duplicate values only : var duplicates = list. GroupBy(x => x. Key). Any(g => g.

How do you find duplicates in a list?

To check if a list contains any duplicate element follow the following steps,

1. Add the contents of list in a set. As set contains only unique elements, so no duplicates will be added to the set.
2. Compare the size of set and list. If size of list & set is equal then it means no duplicates in list.

How can I search and find duplicates?

Method 1 of 2: Using Conditional Formatting Open your original file. The first thing you’ll need to do is select all data you wish to examine for duplicates. Click the cell in the upper left-hand corner of your data group. This begins the selecting process. Hold down the ⇧ Shift key and click the final cell.

How do you remove duplicates from a list?

1. Click any single cell inside the data set. 2. On the Data tab, in the Data Tools group, click Remove Duplicates. The following dialog box appears. 3. Leave all check boxes checked and click OK. Result. Excel removes all identical rows (blue) except for the first identical row found (yellow).

How to find duplicates with first and last names?

If the first name and last name in separate columns, you need to combine them first, then find the duplicate names. In the next column of the first names and last names, type this formula =E2&” “&F2 , drag fill handle down to combine all names. Now you can find the duplicate names.

How do you find duplicate records?

To find duplicate records, use Excel’s easy-to-use Filter feature as follows: Select any cell inside the recordset. From the Data menu, choose Filter and then select Advanced Filter to open the Advanced Filter dialog box. Select Copy To Another Location in the Action section. Enter a copy range in the Copy To control.