Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.Lære Undefined | Data Types and Variables
Introduction to JavaScript

Stryg for at vise menuen

book
Undefined

What is Undefined

Undefined is also a data type in JavaScript just like the null. When a variable is created or declared without assigning any value to it, then the value of the variable will be set as undefined by default.


              
12

            
let age;
console.log(age);
copy
Opgave

Swipe to start coding

Declare a variable numberOfItems and assign the value of undefined to the variable and show the value of the variable.

Løsning

So, undefined variables can also be declared using the undefined keyword.

Switch to desktopSkift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder
Var alt klart?

Hvordan kan vi forbedre det?

Tak for dine kommentarer!

Sektion 3. Kapitel 31
Vi beklager, at noget gik galt. Hvad skete der?

Spørg AI

expand
ChatGPT

Spørg om hvad som helst eller prøv et af de foreslåede spørgsmål for at starte vores chat

book
Undefined

What is Undefined

Undefined is also a data type in JavaScript just like the null. When a variable is created or declared without assigning any value to it, then the value of the variable will be set as undefined by default.


              
12

            
let age;
console.log(age);
copy
Opgave

Swipe to start coding

Declare a variable numberOfItems and assign the value of undefined to the variable and show the value of the variable.

Løsning

So, undefined variables can also be declared using the undefined keyword.

Switch to desktopSkift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder
Var alt klart?

Hvordan kan vi forbedre det?

Tak for dine kommentarer!

Sektion 3. Kapitel 31
Switch to desktopSkift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder
Vi beklager, at noget gik galt. Hvad skete der?
some-alt