The ternary operator a is a very compact,

two-way branch that many programmers use to write very concise code.

The only problem is, is that it's so compact it can be hard to read.

It's called ternary because it involves three expressions.

The first is a boolean that determines which of the next two expressions run.

The ternary operator uses two characters, a question mark and a colon.

These two characters are markers for our condition and our two branches.

Let's see how this works in our two.js file from earlier.

First, let's write our ternary operator, a question mark and a colon.

I'll show you how this works just by copying/pasting from this

if statement above.

Let's take the condition, which is stored in the variable isTrue,

and paste it before the question mark.

If isTrue evaluates to true, then the code after the question mark will run.

If not, the code after the colon will run.

So let's copy and paste the true branch, and

paste it just after the question mark here.

And copy and paste the full branch here at the end.

Don't forget to terminate your statement with a semicolon.

Now, if we comment out our if else statement,

we can see the ternary operator in action.

If we run node two.js in the command line, we get yes log.

If we change isTrue to false and

run it again, we see no is logged.

You can see that the ternary expression is almost exactly like

an if else statement, but with a bare bones syntax.

But there is another way you're likely to see a ternary pop up in the wild.

As an expression.

In JavaScript and expression is something that resolves to a value.

You can assign an expression to a variable and that variable will contain the value.

For example, you can assign var x to equal 2 + 5.

2 + 5 is an expression that resolves to the value of 7.

X isn't going to hold 2 + 5,

it's going to hold the value that the expression returns, which is 7.

In the same way, a ternary expression will return one of it's

two branches as a value, depending on the truthiness of the first operand.

Let's see this in the code to get a better idea.

Instead of logging yes or no to the console directly from the ternary,

let's return one of those values and store it in a variable called yesOrNo.

Then we can log that variable to the console,

When the ternary is a evaluated by the interpreter,

it examines the value of isTrue and

returns the first value of yes if it's true, and no if it i not.

And it's choice will be stored in yesOrNo.

Let's save it and run it again.

Now let's change it to true and run the script again.

Technically, you could use the ternary for a multi-way branching while putting

one expression as the condition for the larger ternary expression.

But this gets messy real quick, and it's not a recommended practice.

If you ever use the ternary expression, it should probably be for

very simple cases where the intent is unmistakable and obvious.

For our last conditional, let's have a look at short circuiting.

I'll see you in the next video.