JavaScript is a popular client-side lightweight scripting language, which means that it can run on the user’s browser while allowing the creation of dynamic and interactive content.
Through JavaScript, a web page will
1. achieve dynamic behavior,
2. perform client-side validation and
3. provide header information of the browser
JavaScript Features
Exhibits Dynamic Behavior:
JavaScript exhibits dynamic behavior that allows the programmer to make changes, if any, during the program’s runtime. In contrast, static programming languages only allow changes before the program compilation.
Performs Client-Side Validation:
Client-side validation means checking the input given by the user on the client side before sending the data to the server. Client-side validation plays a vital role in successfully implementing web applications. Importantly, it checks the data’s validity with an application’s prerequisites. Following such practices will enhance the application’s performance while preventing errors and improving the user experience.
JavaScript employs several methods to perform client-side validation. They include,
- JavaScript Functions
- JavaScript Regular Expressions
- HTML5 Form Validation
JavaScript functions help validate the input data the user presents with an already given set of criteria. For instance, functions are used to validate the input data of a password with an already predetermined criteria set. The predetermined criteria include the password length being at least seven characters, including characters of one numeric, one lowercase, and one uppercase letter.
Numerous Frameworks Employ JavaScript:
Several frameworks employ JavaScript to develop interactive, robust, user-friendly, and dynamic web pages. Frameworks contain libraries and tools to enable developers to build web applications and websites easily and quickly. Some frameworks that employ JavaScript include React, Angular, Vue.js, Node.js, Express.js, Ember.js, jQuery, Backbone.js, and Meteor.
Some other Important Features:
Interpreted Programming Language:
Among the interpreted programming languages, JavaScript is one of the most popular. Generally, programming languages can be categorized into interpreted languages and compiled languages. In interpreted programming languages, the source code is directly executed line by line. In contrast, the source code is converted into machine language format in compiled programming language before the code execution.
Enables Cookies:
The programmer can embed JavaScript into an HTML document to help webpages exhibit dynamic behavior. Importantly, JavaScript provides a valuable component called ‘Cookie ‘to implement session management between multiple client requests to various servers. Session management involves handling several requests securely from a single individual or entity to a web-based service or application.
Contains Variables and Data Types:
JavaScript contains variables and data types. While variables are containers that store data values, there are two sets of data types, including primitive data and non-primitive data. Primitive data types include number, string, boolean, and undefined. Non-primitive data types, which are complex compared with primitive data types, include Objects, arrays, and functions.
Support Operators:
JavaScript uses many operators. While operators are the symbols that perform the logic, operands are the values. For 2+ 2=4, 2 is an example of an operand, and the + symbol is the operator. Some of them include arithmetic, assignment, comparison, and logical operators.
Enable Control Flow Statements:
Control statements are significant for any programming language as they help control the execution flow of a program while making it efficient. JavaScript uses two types of control statements: looping statements and conditional statements.
While ‘looping statements’ help in the repeated execution of a particular code block until the achievement of a specific end statement, ‘conditional statements’ help in code execution only in case of meeting specific requirements or conditions.
Examples of looping statements include for, do while, and while. Examples of conditional statements are if else, else, and if.
Inclusion of Functions:
Among the various building blocks of JavaScript programming language, functions are one type. Before using a function, the programmer first needs to define the function.
The second step involves calling the function. Functions are essential to the JavaScript programming language as they are among the critical building blocks. Functions and procedures are almost similar.
Nevertheless, qualifying as a function requires taking some input values and returning an output.