Javascript Variables
by vsasikalabe Updated: Feb 24, 2023
Guide Kit
A JavaScript variable is used to store the value. You can initialize it with a value once you have declared a variable. To initialize a variable, you can specify the variable name, followed by an equal's sign (=). After that, you can change its value by assigning a different value.
While declaring a JavaScript variable, we have some rules (also known as identifiers).
- It must start with an underscore (), a letter (a to z or A to Z), or dollar ($) sign.
- After the first letter, we can use digits (0 to 9), for example, value 3.
- JavaScript variables are case-sensitive, i.e., a and A are different variables.
JavaScript local variable
A JavaScript local variable is declared value within the block. We can access it within the function or block only.
JavaScript global variable
A variable is declared outside the function or with a window so that we can access it from any function.
4 Ways to Declare a JavaScript Variable:
- var- The var statement declares a value globally scoped variable.
- let - It declares variables limited to the scope of a block statement where it is used.
- const -A constant holds a value that does not change.
- nothing
Start the statement with let and separate the variables by a comma. We can declare many variables in one statement. If you re-declare a JavaScript variable declared with var, it will not lose its value.
Difference between undefined and undeclared variables.
An undefined variable has been declared but not initialized with a value. For example:
let message;
console.log(message); // undefined
Undeclared variables are always global. It has not been declared using var, let, or const keywords.
Here is an example of how to create Javascript Variables:
Preview of the output that you will get on running this code from your IDE.
Code
Instructions
Follow the steps carefully to get the output easily.
- Download and Install VS Code on your Desktop.
- Open the VS Code and install Javascript ES6 Code Snippet and Code Runner from Extensions.
- Open the new file and save as example.js
- Copy the code using the "Copy" button above, and paste it in your javascript file.
- Run the code using (ctr+alt+N) Run button.
I hope you found this useful. I have added version information in the following sections.
I found this code snippet by searching for ' console input output javascript variables' in kandi. You can try any such use case!
Environment Tested
I tested this solution in the following versions. Be mindful of changes when working with other versions.
- The solution is created in VS Code 1.73.1 version.
- JavaScript (ES6) code snippets v1.8.0
- Code Runner v0.11.8
Using this solution, we are able to use Javascript Variables with simple steps. This process also facilities an easy way to use, hassle-free method to create a hands-on working version of code which would help us to use Javascript Variables.
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