Check if a list has duplicate numbers [Quick tip]
A while ago (well more than 3 years ago), I wrote about an array formula based technique to check if a list of values have any duplicates in them.
Today, lets learn a simpler formula to check if a list has duplicate numbers.
Assuming you have some numbers in a range B4:B10 as shown below, we can use MODE + COUNTIF formulas to check if there are any duplicate values in a list.
Formula Forensics 011. Lykes Formula
Lykes asked Formula Forensics “How does a formula work?” Lykes has been using the formula without understanding it.
The formula counts how many times the letters from a list of letters occur in a list of words.
Today we look at a Lykes question.
Comparing 2 Lists with a Twist
We love to compare. The instinct to compare leaves no one. Even my two year old twins compare their toys with each other (and fight).
It would make Excel hugely popular if Microsoft builds a handy data comparison tool right in to it. Alas, they have customizable ribbon, 3d effects & equation editor…
Since comparison is one of the main uses of Excel, we have written extensively about it here.
But there is always one more interesting comparison problem. Today, I want to share one such problem, based on a comment left by N-Man.
Formula Forensics No. 010 Count How Many Times a List of Values Occurs in a Range
Count How Many Times a List of Values Occurs in a Range
(or How Can I Simplify My Formula)
Today in Formula Forensics we look at how to count how many times a range of values occurs within a Range of cells and in the process simplify a very nasty formula.
Formula Forensics No. 003 – Lukes Reward
Today we publish what is hopefully the First of many posts by guest author Luke M. it is also the Third post in the Formula Forensics series, which has now moved to a regular and new Thursday slot ?
Luke has taken up Hui’s and 3G’s challenge of explaining how the technique he regularly uses on the Chandoo.org Forums for extracting individual records out of a group.
Today Luke tells us how to extract a list of items from a larger list according to some criteria.
Using an Array Formula to Find and Count the Maximum Text Occurrences in a Range
Chandoo is off on Holidays and once again thrown me the keys to Chandoo.org.
So this week we’re going to:
- Pull apart an Array Formula and see what’s under the hood;
- Have a look at a technique for quickly developing Custom Number Formats &
- Look at how we can use HTML Codes in posts at Chandoo.org to spice up your questions and answers.
Today is Tarun’s Problem
“I have got multiple names in each row and would like to have what name is repeated maximum number of times and how many times?”
Today we pull apart an answer to this question and see how it works.
Compare 2 Lists Visually and Highlight Matches
Comparison is one of the most common things we do with Excel. Naturally, there are so many ways to compare 2 lists of data using Excel.
Today, I want to share an interesting comparison problem with you.
Lets say you run a small shop which sells some highly specialized products. Now, since your products require quite some training before customers can buy them, you keep track of all product queries and arrange demos.
After a hectic week, you are staring at 2 lists. One with product queries, another with product demos. And you want to know whether all the queries are answered with a demo or not.