Excel has a really powerful and convenient feature
called functions.
A function is a pre-defined formula, and it's used
when a formula
would be too complicated, or just too long.
You can access them from the Formulas tab.
There are hundreds of functions that you can choose from,
and they are organized by category in the function library.
For example, the Financial category contains functions that
deal with things like interest and monthly payments.
The Text category allows you to convert text to
lowercase or uppercase,
replace text, and do other types of text manipulation.
Date & Time includes functions that return the
current date, time, day of the week, and others.
And there are many more functions.
Much of the time, you'll just need to use common
functions such as SUM and AVERAGE, and you can
access these by clicking the AutoSum drop-down arrow.
In this example, I'd like to add all of these cells.
If I tried to create a formula for this, I would
have to add each one individually.
That would get pretty long, and if I had to add
hundreds of cells,
then it would really not be manageable at all.
So I'm just going to add them all by using a
function.
Click on the cell where you want the function to
be, and then
click on the AutoSum drop-down arrow and select Sum.
Now this has inserted the function, and it's also
selected the cells that are being added.
If it selects the wrong cells, then we can always
change that by dragging these corner handles.
But this looks right, so I'll press enter to get
the result.
Let's look at this function in a little bit more
detail.
Just like formulas, functions always start with
the equal sign.
But you might notice that there are no mathematical operators such as addition or
subtraction, like you would normally see in a
formula.
Instead, functions have a specific syntax that
includes the name of the function,
followed by one or more arguments in parentheses.
The arguments tell the function which cells or
numbers to use to calculate the result.
In this example, we actually only have one argument,
even though there are two different cell references.
This is called a range of cells.
A range of cells is indicated by two cell references separated by a colon.
In this case, the range consists of all of the
cells from F6 to F14.
If you want to use more than one argument, you'll
need to separate them with commas.
Let's try a different function now.
In this example, we have a column for the date
that each item was ordered,
and the date that it was received, and I'd like to know how many
business days it took to receive the item after it
was ordered.
First, select the cell where you want the function
to go.
If you know which category your function is in,
you can select it from there, or you can just
search for the function by clicking the Insert Function command.
Just type in a description of what you're looking
for.
I'm looking for a function that can count the
number of days elapsed,
so I'll type "count days" and press Enter.
We've gotten a lot of different results here.
You can click on a function and read a description of it below.
NETWORKDAYS returns the number of workdays between
two dates, and that's what we want.
So I'll click OK.
There will be a field for each argument.
This function has up to three arguments: Start_date, End_date, and Holidays.
When you click in each field, you can see a
description of it below.
If you need more help on a particular function, you can click "Help on this function".
I'll select G6 for the Start date, H6 for the end
date, and the
Holidays argument is optional, so I'll just leave it blank.
You'll be able to see the result here.
Click OK, and the function will be added to the
worksheet.
Just like with formulas, we can drag the fill handle to copy it.
And now we can see how long it took each of these
items to arrive.
If you've never used functions before, the syntax
may seem a little strange at first,
but with some practice you'll start to get the hang of it,
and over time you'll probably find your favorite functions that you'll use over and over again.