All language subtitles for 007 Revisiting Operators_en

Select and const are super important.

Another very important concept related to values

are operators.

For example, in JavaScript we can perform math.

We can use the plus, minus, times,

and division operator to perform math,

and to, for example, divide 10 by five.

And what's important to know about JavaScript

is that the plus operator for adding things

cannot just be used for numbers, as I'm doing it here.

And the difference between numbers and strings

is that they don't have quotes around them.

But instead it can also be used with text.

For example, "hello" plus "world"

for concatenating two strings into one longer string.

With that code,

we would get helloworld like this as one word,

because I have no blank anywhere in these strings.

But as you can see,

the plus operator works absolutely fine here.

So you can also use it for concatenating strings.

Now, besides plus, minus, times and division,

you also have some other crucial operators.

For example, the triple equal sign operator,

which is used for checking for equality.

And this operator therefore yields a Boolean value.

In this case here, false, because 10 isn't equal to five.

If I would be checking 10 equals 10,

I instead would be getting true.

Now, besides checking for equality,

you can also check for things being greater or smaller

than other things,

or greater or equal or smaller or equal.

And these comparison operators are also very commonly used

in JavaScript

and will be used a lot in this course,

typically in conjunction with the if keyword

and if statements,

which allows you to execute some code conditionally.

For example, here I'm comparing 10 to 10,

which is kind of redundant of course.

Typically you would instead compare some dynamic user input.

But for this demo here, I'm using two hard coded values,

and if this condition is met,

which in this case here will of course always be the case,

the code in the if statement will execute.

But I'll get back to if statements a little bit later again.

Here, if I reload this idea for get works,

because of course this condition here is always met.

Again, this is a redundant condition.

In this course, in the apps we're going to build with React,

you will see conditions that make more sense.