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JavaScript JavaScript Basics (Retired) Making Decisions with Conditional Statements Boolean Values

Samantha Atkinson
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Samantha Atkinson
Front End Web Development Techdegree Student 36,955 Points

Conditional Statements and Boolean values Have I Understood Them?

Hi someone has probably asked this question, however, I want to know if I have understood everything, so far:

  1. A conditional statement is the if ( ) { } you don't have to add the else part, the if () {} is considered the conditional statement?

    1. Conditional statements, the if part if ( ) { } only return true or false?
    2. Booleans are values themselves true or false values?
    3. So by adding the boolean value false in the if ( false ) { } the if condtional statement is the reason why the else condition kicks in Dave's demo of the boolean values.

I think why it's confusing is because before we were adding variables with values in them and using the strict Equal To operator to test if the condition was true or false. However, by using the boolean values we are actually giving the conditional statement the outcome or value of the if statement basically without having to test if true or false?

I hope how I have worded it makes enough sense that someone can tell me if I have truly understood it all.

Thanks in advance for any answers

2 Answers

Steven Parker
Steven Parker
229,670 Points

It sounds like you have most of it. To confirm:

  • an "if" is a conditional statement (with or without an "else" following it)
  • the expression inside an "if" evaluates to true or false :point_right: if ( <expression goes here> ) ...
  • Boolean values are either true or false
  • the body of an "if" that has "false" as its expression will never run
  • the body of an "else" that follows an "if" with "false" as its expression will always run

And don't worry, all of these concepts will become more clear as you gain experience working with them.

Samantha Atkinson
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Samantha Atkinson
Front End Web Development Techdegree Student 36,955 Points

Thank you, Steven, once again coming to my aid. I hope they do become clearer with experience. Thanks for answering with technical terms, like expressions.

Jamie Reardon
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Jamie Reardon
Treehouse Project Reviewer

Hey Sam!

To answer your first question, yes! A conditional statement can be declared with an if keyword and the parenthesis. You don't have to add an else clause if your program doesn't need it. It is just a fall back for when the condition check fails and you want to run some code.

You can also add an else if clause for multiple program outcomes. The first else if clause will only run if the first if condition fails, and so on. Therefore, keep in mind that only one condition code-block will ever run.

Conditional statements, the if part if ( ) { } only return true or false?

The if statement by default, checks for a true condition. So, if you have boolean values, you could pass the variable holding the boolean value into the condition. For example:

let correctGuess = true;
if (correctGuess) {
// code
}

You can switch the default behaviour by using the not operator like so:

if (!correctGuess) {
// code
}

Booleans are values themselves true or false values?

Not sure I understand this question? But from what I can understand, you are asking if booleans are values like other data types such as numbers and strings? if so, then yes and there are only two: true and false.

Samantha Atkinson
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Samantha Atkinson
Front End Web Development Techdegree Student 36,955 Points

Hey Jamie, thank you for replying TechDegree buddy 👊. Oh wow, you gave me a whole lot more too, then just the answers to my question. I was just going over the video and kind of stopped to process at the point Dave just creates a conditional statement demo just using the booleans true and false as the expression at the beginning of the video.

I needed to know if I was getting the concept before he then starts with giving the variable correctGuess the value false because at that point I thought I need to watch from the beginning again lol.

Jamie Reardon
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Jamie Reardon
Treehouse Project Reviewer

Hey Sam!

Haha no worries! :) Glad it gave you some insight into conditional logic in js! I also struggled to understand the concept at first as well! But just to keep on mind, if you ever see or create a variable that holds a boolean value, it can be used as the condition since the conditions are only really searching for true or false checks!

See you on slack! :)