What are the knowledge points about javascript?

As a widely used programming language, Javascript (JS) has become one of the essential skills for front-end developers. Next, let’s learn about some knowledge points in Javascript.

1. Variables and data types

In JS, we can use keywords such as var, let, and const to declare variables. Data types in JS are divided into basic data types and reference data types, including numbers, strings, Boolean values, objects, arrays, etc. Understanding the different characteristics of different data types can help us program more efficiently.

2. Operator

Operators in JS include arithmetic operators, comparison operators, logical operators, bitwise operators, etc. Understand the priority of each operator and usage methods can reduce code redundancy and errors.

3. Control flow

In JS, we can use if/else statements, switch statements, for/while loops and other control flow statements to control the execution flow of the program. Mastering the use of these statements can help us better organize code logic and achieve various needs.

4. Function

Function is an important part of JS, which can help us encapsulate a piece of code and achieve code reusability and scalability. Understanding function definition, calling, parameter passing, return values, etc. can allow us to write JS code more efficiently.

5. Objects and object-oriented programming

Objects in JS are reference data types that can contain properties and methods, and can be used for object-oriented programming such as inheritance and polymorphism. characteristic. Understanding the concepts and principles of objects and object-oriented programming can help us better organize program structures and implement various needs.

6. Arrays and Strings

Arrays and strings are commonly used data types in JS. We can use arrays to store and operate multiple values, represented by strings and operational text information. An in-depth understanding of the characteristics and methods of these data types can help us implement complex requirements more efficiently.

7. DOM operation

JS can be used to manipulate elements in HTML documents, including obtaining, creating, deleting, modifying the attributes and content of elements, etc. DOM operations are a very important part of JS. Mastering DOM operations can help us achieve various needs for interacting with users.

8. Ajax

Ajax is the abbreviation of asynchronous JavaScript and XML, which can help us achieve asynchronous data interaction by sending HTTP requests and processing responses. Understanding the principles and usage of Ajax can help us better interact with front-end and back-end data and improve user experience and page performance.

9. New features of ES6

ES6 is a version of JavaScript that introduces many new features, including arrow functions, template strings, destructuring assignment, classes and modules, etc. . Learning the new features of ES6 allows us to write more efficient and readable JS code.

Summary

The above are some important knowledge points in JS. Understanding these knowledge points can help us write JS code more efficiently and cope with various development needs. Of course, JS learning requires continuous practice and accumulation of experience, and continuous in-depth study and practice can master more advanced skills and applications.

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