


Deletion method of elements in JScript built-in object Array_javascript skills
We know that JScript provides us with a built-in array object Array. In addition to providing constructor, length and prototype, the Array object also provides 13 methods by default: concat, join, pop, push, reverse, shift, slice, sort, splice, toLocaleString, toString, unshift and valueOf, but does not provide delete method.
If you are familiar with JavaScript, you will immediately say that the system provides a delete operation that can be used to delete elements in an array. Yes, there is indeed a delete in the JS system that can delete elements in the array. But this deletion is difficult to use. It can indeed delete elements, but it does not update the element counter of the Array object. For example, we execute:
var ary = ['a', 'b', 'c'];
delete ary[1];
If the deletion is executed correctly, we hope to get A new array has two elements ['a', 'c'] and has a length of 2. But after execution, we did get an array with two elements ['a', 'c'], but the length of this new array is still 3!. At the same time, when we execute ary.toString(), we will get "a,,c", which also shows that the counter of the array is still 3, because Array's toString() actually executes Array.join(',').
Such deletion will be very frustrating when we use for( ; ;) to traverse the array, and we may easily be killed by an undefined value. So how can we get the size of the synchronized array after deleting the array elements? Since the pop and shift functions provided by Array itself can "really" delete elements of the array, we can use them to expand a remove function ourselves.
But pop and shift can only delete elements from both ends of the array, so we need to do some sorting of the array before deleting. The code to implement the remove method is as follows:
Array.prototype. remove = function(obj)
{
for (var i=0; i {
if (this[i] == obj)
{
{
this[j] = this[ j 1]; }
This.pop (); }
Else
{
for (var j = i; j> 0; --j)
{
break;
}
}
} ;
The purpose of moving and sorting the array is just to not change the relative positions of the remaining elements after deleting the elements. Otherwise, just swap the elements that need to be deleted to the pop or shift below the two ends.

JavaScript originated in 1995 and was created by Brandon Ike, and realized the language into C. 1.C language provides high performance and system-level programming capabilities for JavaScript. 2. JavaScript's memory management and performance optimization rely on C language. 3. The cross-platform feature of C language helps JavaScript run efficiently on different operating systems.

JavaScript runs in browsers and Node.js environments and relies on the JavaScript engine to parse and execute code. 1) Generate abstract syntax tree (AST) in the parsing stage; 2) convert AST into bytecode or machine code in the compilation stage; 3) execute the compiled code in the execution stage.

The future trends of Python and JavaScript include: 1. Python will consolidate its position in the fields of scientific computing and AI, 2. JavaScript will promote the development of web technology, 3. Cross-platform development will become a hot topic, and 4. Performance optimization will be the focus. Both will continue to expand application scenarios in their respective fields and make more breakthroughs in performance.

Both Python and JavaScript's choices in development environments are important. 1) Python's development environment includes PyCharm, JupyterNotebook and Anaconda, which are suitable for data science and rapid prototyping. 2) The development environment of JavaScript includes Node.js, VSCode and Webpack, which are suitable for front-end and back-end development. Choosing the right tools according to project needs can improve development efficiency and project success rate.

Yes, the engine core of JavaScript is written in C. 1) The C language provides efficient performance and underlying control, which is suitable for the development of JavaScript engine. 2) Taking the V8 engine as an example, its core is written in C, combining the efficiency and object-oriented characteristics of C. 3) The working principle of the JavaScript engine includes parsing, compiling and execution, and the C language plays a key role in these processes.

JavaScript is at the heart of modern websites because it enhances the interactivity and dynamicity of web pages. 1) It allows to change content without refreshing the page, 2) manipulate web pages through DOMAPI, 3) support complex interactive effects such as animation and drag-and-drop, 4) optimize performance and best practices to improve user experience.

C and JavaScript achieve interoperability through WebAssembly. 1) C code is compiled into WebAssembly module and introduced into JavaScript environment to enhance computing power. 2) In game development, C handles physics engines and graphics rendering, and JavaScript is responsible for game logic and user interface.

JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Dreamweaver Mac version
Visual web development tools

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function
