This is part of our Excel Interview Questions series. Subscribe for more questions.
VLOOKUP or INDEX+MATCH? When you should use each function and why?
This is such a great question to ask in interviews. So in my first installment of Excel interview questions, let me answer it.
Watch the answer – video
I made a video explaining both formulas and how to answer such interview question in detail. There is a quick demo of VLOOKUP, INDEX&MATCH and array use of INDEX too. Watch it below or on Chandoo.org YouTube Channel.
What is VLOOKUP?
VLOOKUP is Excel’s data search function. Given some data, you can use VLOOKUP to answer questions about it. Say you have data like this,
You can use VLOOKUP to answer questions like,
- How many customers did “Jonathan” have?
- What is the net sales for “Jessy“?
Example VLOOKUP formulas:
To answer above questions, we can use below formulas:
- VLOOKUP(“Jonathan”, Sales, 2, false)
- VLOOKUP(“Jessy”, Sales, 3, false)
What is INDEX+MATCH?
INDEX+MATCH combination formula helps you answer same questions as VLOOKUP, but they also allow you to answer questions about data from anywhere (not just the left most column).
For example, you can answer questions like:
- Who had net sales of 2,133?
- Whose profit is 570?
- What is net sales of “Jessy“?
Example INDEX+MATCH formulas:
To answer above questions, you can use below INDEX+MATCH formulas.
- =INDEX(Sales[Sales Person], MATCH(2133, Sales[Net Sales], 0))
- =INDEX(Sales[Sales Person], MATCH(570, Sales[Profit / Loss], 0))
- =INDEX(Sales[Net Sales], MATCH(“Jessy”, Sales[Sales Person], 0))
When to use VLOOKUP?
VLOOKUP is a good option when you have simple data or lookup situations. Let’s say you just need to lookup details for someone or something out of a any sized data-set. Use VLOOKUP. It is easy to use and works as long as you are looking up on the left and returning values from right.
When to use INDEX+MATCH?
INDEX+MATCH combination is good for,
- Looking up anywhere in data (not just in the left)
- with large data-sets
- when performing multiple lookups (usually thousands or more)
Why not just use INDEX+MATCH all the time?
This depends on your style. I prefer to use VLOOKUP for simple situations as it is easy to write. But whenever I am building a complex report or model with thousands of lookups, I try to use INDEX+MATCH formulas.
How to make lookups faster?
The best way to make lookups faster is by avoiding them. We can use relationships feature of Excel to connect tables and analyze without writing multiple lookup formulas.
But if you can’t use that, then rely on INDEX+MATCH structure as it allows better performance. To speed up lookups, follow below ideas:
- Sort your data. If you can sort your data, that will make lookups very fast. You can omit the FALSE or 0 parameter in VLOOKUP / MATCH formulas with sorted data. Of course, the result will be wrong if what you are looking for is not there. But this can be solved by using an IF formula like this:
- On sorted tables, =IF(MATCH(“Jessica”,Sales[Sales Person])<>”Jessica”, “Not found”, INDEX(Sales[Net Sales], MATCH(“Jessica”, Sales[Sales Person])))
- Lookup once, get many times. For example, if you have multiple INDEX+MATCH formulas all doing same MATCH, then calculate the MATCH result once in a cell and refer to that in INDEX formulas.
- Use array notation of INDEX. We can return arrays with INDEX formula. This tends to be faster than writing multiple INDEX formulas.
- Use Dynamic Array functions (NEW). Excel 2019 is going to introduce powerful array functions like FILTER(), SORT() etc to dynamically generate array of results from your questions. If you have access to them, consider using them over normal array INDEX formulas.
Learn more about lookup formulas
If you want to learn all about VLOOKUP, INDEX+MATCH or other lookup techniques, check these links.
- All about VLOOKUP and INDEX+MATCH formulas
- VLOOKUP multiple matches – trick
- INDEX formula and arrays
- Lookup last value
- The ultimate lookup trick – Multi-condition vlookup
What is your answer?
Imagine you have this question in an interview. How would you answer it. Please share your response in comments.
Also, if you have any suggestions for Excel Interview Questions series, please post or email. 🙂
22 Responses to “Formula Forensic No 019. Converting uneven Text Strings to Time”
Why not let the TIME function take care of the math:
=TIME(LEFT(TEXT(A1,"000000"),2),MID(TEXT(A1,"000000"),3,2),RIGHT(TEXT(A1,"000000"),2))
I was going to point out the same thing, except to note that useing the time function and doing the divide method are not interchangeable.
I have spent hours investigating a spreadsheet working with a couple of years worth of hourly data, and found that the reason things weren't working is because the rounding on the divide method is only close to the correct time values. In order to have it work for comparisons, (like sub-totaling by time value, or pivoting) you MUST use the TIME function.
Great use of the TEXT function, Hui. I will be using this concept for sure.
Why not just.
=TEXT(A1,"00\:00\:00")*1
Regards
Elegant!
Hi Elias,
I tried to use your formula. But, it doesn't seem to work for me. I am getting an error message "The formula you typed contains an error". It seems I have the problem in using \: in the format. How can I overcome this?
Thanks
Manick, it isn't the /: that causes the problem. If you copy/paste it, you're getting “'s instead of the actual quotation marks that Excel uses. Change the quotation marks by deleting from the pasted formula and retype them.
Hi Manick...
use this alternate formula :
=1*TEXT(A1,"00"":""00"":""00")
note twice double quote each side of :
@Manick,
Did you copy the formula and pasted in Excel or did you typed? Also, do you use , or ; as separator of arguments?
Regards
@Elias: I had no problem using your formula, in fact, I have used your method to convert a number such as 20120419 to an Excel date using =TEXT(A1,"0000\/00\/00")*1. Thanks for posting.
@Joe: For date convertion you can use this as well.
=TEXT(A1,"00-00-00")*1
Regards
Sweet! It appears this also works with =TEXT(A1,"0-00-00")*1. I come from the old days when you counted every byte. I also like to try an make formulas as small as possible for the fun of it 🙂
Elias's suggestion is the simplest, but here is yet another way with TIME and MOD functions...
=TIME(MOD(A2/10000,100),MOD(A2/100,100),MOD(A2,100))
Since the seconds appear to always be 0, why not simply the input to minutes and above and save yourself the trouble of typing those zeroes...
0 => 0:00
1 => 1:00
10 => 10:00
100 => 1:00:00
etc.
Then just use this formula...
=TEXT(A1,"0\:00\:")*1
@ Rick, the numbers to convert are no typed, they are imported. Then your formula will return the wrong result.
Regards.
Hmm! My formula lost some backslash-zero combinations (two of them to be exact). The formula was supposed to be this...
=TEXT(A1,"0\:00\:\zero\zero")*1
where the words "zero" should actually be the number 0. Another way to write the formula is this...
=TEXT(A1,"0\:00\:""00""")*1
Hi Master,
While writing the formulae you have considered only upto "seconds factor" . I think you should take the centi-seconds factor also to achieve best results. Please look into it and rectify the problem...?
For Example.
In horse racing timings are noted in minute, seconds and centi-seconds, like if a horse finished in 70 seconds over a scurry of 1200 metres, is noted as 1.10 min. Nowadays it is noted in centi-seconds everywhere, like 70.00 if you want to convert it to centi seconds (should multiply by 100) = 7000 centi seconds. If you put this figure into your formula as a general number (7000) it will return as 1:10:00. As per your formula, it should be taken as 1 hour 10 seconds 0 minutes. However for a racing enthusiast like me it can be taken as 1 minute 10 seconds also.
Just look what happens if we race goers use this figure as 7000 centi seconds in your formulae, it will correctly show as 1 minute 10 seconds(?) Suppose a horse finishing over a 1200m in 70.60 seconds or in racing terms written as 1.10.60 mins, where 1 minute 10 seconds, & 60 centi-seconds can be counted as 7060, if you put this figure in the formula it will return as 1 minute 11 seconds, that is correct.
My point is if you can incorporate Centi Seconds in the formulae, it would be of great help to us also.
Thanks and regards.
Rajagopal (Mumbai)
Awesome techniques !
I tried with 235960 just to see if it will fail but this is great.
Although a little longer, this too work:
=CHOOSE(LEN(A2);A2/(24*3600);A2/(24*3600);LEFT(A2;1)/(24*60) + RIGHT(A2;2)/(24*3600);LEFT(A2;2)/(24*60) + RIGHT(A2;2)/(24*3600);LEFT(A2;1)/24 + MID(A2;2;2)/(24*60) + RIGHT(A2;2)/(24*3600);LEFT(A2;2)/24 + MID(A2;3;2)/(24*60) + RIGHT(A2;2)/(24*3600))
Converting uneven Text Strings to Time I have imported some data that comes in as a number that I need to convert to h:mm.
Just come across this while googling
find interesting challenge and come up with this
=TEXT(TEXT(SUBSTITUTE(A1,RIGHT(A1,1),""),"000000"),"00\:00\:00")
I need to convert a string of numbers representing average minutes, to reflect correct time values. For example, the numbers below currently represent 5.79 minutes, 15.82 minutes, etc.
I need to convert these values to their correct corresponding value within time parameters. So 5.79 would be something close to 5 minutes and 45 seconds.
5.79
15.82
3.92
12.40
6.70
3.62
I know there has to be a way to compute this in Excel, it can do anything, I believe!
Thank you for any and all assistance~
@Renee... You can use a formula like this. Assuming A1 has the minutes.seconds,
=INT(A1) + MOD(A1, 1)*0.6
If you want to see it in 5 minutes 45 seconds format, use
=INT(A1) & " mins " & ROUND(MOD(A1, 1)*0.6,2) & " secs"