React JS Training Course Online
- 21k Enrolled Learners
- Weekend
- Live Class
(7200)
In any programming language, a reserved word or a reserved identifier is a word that cannot be used as an identifier, such as the name of a variable, function, or label. Thus, it is reserved and cannot be used for defining any of these. This is a syntactic definition, and a reserved word may have no meaning. In this article, we will discuss some of the JavaScript reserved words and their description.
JavaScript Reserved Words
Here is a list of JavaScript Reserved words along with their definition:
| Reserved Words | Description |
abstract | Abstract is a non-access modifier which is applicable for classes, methods but not variables. |
arguments | Argument is an array-like object lists the arguments and a few other properties. |
await | The keyword Await makes JavaScript wait until the promise returns a result. |
boolean | Boolean is used as a function to get the value of a variable, object, conditions, expressions, etc. in terms of true or false. |
break | It breaks the loop and continues executing the code after the loop. |
byte | This uses the javascript typeof() operator to detect what kind of type is variable x and y. |
case | The switch statement evaluates an expression. The value of the expression is then compared with the values of each case in the structure. |
catch | This statement allows you to define a block of code to be executed if an error occurs in the try block. |
char | The char keyword is a data type that is used to store a single character. |
class | Classes are another way of writing constructor functions which can be used in order to create a new object using the new keyword. |
const | The const keyword is used to declare the constant in the function scope. |
continue | Continue statement jumps over one iteration in the loop. |
debugger | This statement stops the execution of JavaScript and calls the debugging function. |
default | The default keyword can be within a switch statement, or with an export statement. |
delete | You can use the delete keyword to delete the value of the property and the property itself. |
do | The do/while statement is used when you want to run a loop at least one time. |
double | JavaScript numbers are always stored as double precision floating point numbers |
else | It is a part of JavaScript’s Conditional Statements and you can use this to perform different actions based on different conditions. |
enum | The enum keyword declares an enumerated type. |
eval | The eval() function evaluates or executes an argument. |
export | The export statement is used when creating JavaScript modules to export functions, objects, or primitive values from the module. |
extends | The extends keyword is used in class declarations or class expressions to create a class which is a child of another class. |
false | JavaScript includes a Boolean object to represent true or false. It considers null as false. |
final | Final keyword is used to state that a value, class, or method cannot be changed. |
finally | The finally statement lets you execute code, after try and catch, regardless of the result. |
float | JavaScript numbers are always stored as double-precision floating-point numbers. |
for | The for statement creates a loop that is executed as long as a condition is true. |
function | A function is a JavaScript procedure that performs a task or calculates a value. |
goto | The goto is accomplished in JavaScript using the break and continue keywords. |
if | You can use if to specify a block of code to be executed if a specified condition is true. |
implements | The implements keyword is used to implement an interface. |
import | The import keyword is used to call the function to import the module dynamically. |
in | The in operator returns true if the specified property is in the specified object or its prototype chain. |
instance of | The instanceof operator in JavaScript is used to check the type of an object at run time. |
int | It converts a primitive datatype, string, or array to its integer representation. |
interface | The interface keyword is used to declare a special type of class that only contains abstract methods. |
let | let allows you to declare variables that are limited to a scope of a block statement, or expression on which it is used. |
long | Long represents a 64 bit two’s-complement integer value |
native | The native keyword is applied to a method to indicates that the method is implemented in native code. |
new | The new keyword constructs and returns an object of a constructor function. |
null | Null in JavaScript that signifies ‘no value’ or nonexistence of any value. |
package | A package is a directory with one or more modules inside of it and a package.json file wich has metadata about the package. |
private | A private function can only be used inside of its parent function or module. |
protected | A public function can be used inside or outside of its parent function or module. |
public | The protected keyword is an access modifier used for attributes, methods and constructors, making them accessible in the same package and subclasses. |
return | Return statements cease execution in a function and return a value to the caller. |
short | It is used to represent an integer value in JavaScript. |
static | The static keyword defines a static method for a class. |
super | The super keyword is used to access and call functions on an object’s parent. |
switch | The switch statement evaluates an expression. |
synchronized | synchronous code is executed in a sequence where each statement waits for the previous statement to finish before executing. |
this | The JavaScript this keyword refers to the object it belongs to. |
throw | Throw is the keyword that is used to raise an exception. |
throws | The throws keyword indicates what exception type may be thrown by a method. |
transient | Transient is a variables modifier used in serialization. |
true | Boolean datatype returns either of two values i.e. true or false. |
try | The try statement allows you to define a block of code to be tested for errors while it is being executed. |
typeof | typeof is a JavaScript keyword that will return the type of a variable when you call it. |
var | var is used to declare the variable in JavaScript. |
void | The JavaScript void operator evaluates the given expression and then returns a value of undefined. |
volatile | Volatile keyword is a qualifier that is applied to a variable when it is declared. |
while | The while statement creates a loop that is executed while a specified condition is true. |
with | The with statement extends the scope chain for a statement. |
yield | The yield keyword returns an IteratorResult object with two properties and value. |
With this, we come to the end of this “javascript reserved words” article. I hope you found it informative.
Related Post Methods for detecting and preventing clickjacking with JavaScript
Now that you know about JavaScript Reserved Keywords, check out the Web Development Certification Training by Edureka. Web Development Certification Training will help you Learn how to create impressive websites using HTML5, CSS3, Twitter Bootstrap 3, jQuery and Google APIs and deploy it to Amazon Simple Storage Service(S3).
Check out the Angular Certification Training Course by Edureka, a trusted online learning company with a network of more than 250,000 satisfied learners spread across the globe. Angular is a JavaScript framework that is used to create scalable, enterprise, and performance client-side web applications. With Angular framework adoption being high, performance management of the application is community-driven indirectly driving better job opportunities.
If you want to get trained in React and wish to develop interesting UI’s on your own, then check out the React JS Certification Course by Edureka, a trusted online learning company with a network of more than 250,000 satisfied learners spread across the globe.
Got a question for us? Please mention it in the comments section of “JavaScript Reserved Keywords” and we will get back to you.
