All language subtitles for 6. Control Flow - Relational Operators

Hi there, guys.

In this video, we are going to talk about relational operators.

Well, the name itself is kind of scary, but there is no need for panic just yet.

Relational operators are used in conditions and they simply tell you how you are going to ask a certain

question.

For example, how you are going to ask if a grade is higher than 80.

In our programming language and actually we've seen a couple of examples in the previous videos where

we use these relational operators probably without even noticing that.

And to tell you the truth, guys, you as a future programmer, you must be familiar with all of these

terms that we've used so far and all of the terms that we are going to use in these course.

And that's why in this video, we are going to talk about it in more detail and use a little bit of

more formality.

So we talked about different rules that should be followed in every programming language.

You do remember that, right?

So the same goes here.

There are things and rules that should be applied when constructing conditions.

Now you sing.

I sing most of the programming languages when you would like to ask a question.

It won't be simply enough to ask for it in English.

Something like if grade is greater than 80.

So we are interested in constructing the conditions in our programming language, just like we've seen

in previous examples.

And that's exactly the place and the time when we would like to use relational operators that will help

us with this task.

So relational operators are just these signs, which you've probably seen most of them somewhere before,

maybe even on your math classes.

And the first one, the greater them, helps in constructing a condition to check if the left side is

greater than the right side.

Then we have the greater than or equals two, which is pretty much the same.

It simply checks if the left side is greater than the right side or if the left side equals to the right

side.

So if either of these options happens to be true, then the result of the condition will be true.

So in most cases, if we would like to ask a question like if grade is greater than 80, we are probably

going to do it in this way.

We are going to use of the greater than relational operator assign and simply put, the grade, which

is a variable on its left and the value of eighty on its right.

And if this condition happens to be true, meaning that grade is actually is greater than 80, we are

going to execute some of their following commands that we would like to execute.

And the same goes for the less then and the less then or equals to science.

They are pretty much the same as we use the greater than the last.

Then checks of the value on its left is less than the value on its right.

And if that's the case, the result of the condition is going to be true.

We also may have times when we would like to check if the user has done a great job on his last exam.

So probably we are going to check if the grade was, for example, let's say a hundred.

So for that, we are going to use the equals to sign.

Please note that there are two of these signs right here.

And one, they are used this way when they come in despair.

They check the equality between what is on its left side to what is on its right side.

Otherwise, if you wouldn't have used just one of them, then you know that it won't be used to check

any condition, but rather it would simply be an assignment operation like we've seen Prieur in the

previous videos and in the previous section.

So that's an important note, guys.

Please make sure you do not mess around with this.

And here is an example of how to use the equals to logical operator check.

So you use if grade.

Then use the equals to sign.

And you use 80 or a hundred to just check that.

You did grade on your last exam.

And lastly, we also have the not equals to sign this operator as simply means that if we have it as

part of our condition and the value on its left does not equals to the value on its right, then the

result of the condition is going to be true.

The same as equals to just the opposite.

And if you would like to write a condition to make sure that you didn't run out of cash.

Meaning that we don't have a zero to our account.

You should use the.

That equals sign just like this.

And let's hope that these conditions shall always remain true.

Definitely not less then.

Don't let it be less than zero.

That's a problem.

All right.

So this is it for this video.

Now we know water relational operator, seeing how they can be used and now we are ready to move on

to our challenges.

So I'll see you there, guys.