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The ternary operator a is a very compact,

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

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

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It's called ternary because it
involves three expressions.

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

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

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

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

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

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

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if statement above.

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

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and paste it before the question mark.

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

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If not, the code after the colon will run.

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

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paste it just after
the question mark here.

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

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

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Now, if we comment out
our if else statement,

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we can see the ternary operator in action.

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

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If we change isTrue to false and

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run it again, we see no is logged.

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You can see that the ternary
expression is almost exactly like

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

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

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As an expression.

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

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

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

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

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X isn't going to hold 2 + 5,

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

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

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

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

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

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

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Then we can log that
variable to the console,

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When the ternary is
a evaluated by the interpreter,

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it examines the value of isTrue and

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

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And it's choice will be stored in yesOrNo.

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Let's save it and run it again.

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

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

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one expression as the condition for
the larger ternary expression.

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

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

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very simple cases where the intent
is unmistakable and obvious.

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

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I'll see you in the next video.