What does es6 syntactic sugar mean?
es6 syntax sugar refers to the syntax in a programming language that can more easily express an operation; using syntax sugar can increase the readability of the program, thereby reducing the chance of program code errors. The new syntax sugar in ES6 is actually ES5 can also be implemented, but it will be slightly more complicated.
The operating environment of this tutorial: Windows 10 system, ECMAScript version 6.0, Dell G3 computer.
es6 What does syntactic sugar mean?
About the understanding of syntactic sugar:
refers to a certain grammar added to computer language. This grammar It has no impact on the functionality of the language, but it is more convenient for programmers to use. Generally speaking, using syntactic sugar can increase the readability of the program, thereby reducing the chance of program code errors.
The new syntactic sugar added in ES6 can actually be implemented in ES5, but it will be slightly more complicated
In computer science, syntactic sugar refers to the easier expression in programming languages. An operation syntax that makes it easier for programmers to use the language: operations can become clearer, more convenient, or more in line with programmers' programming habits.
For example, many programming languages provide syntax for referencing and updating arrays;
Essentially, accessing array elements is the following process:
Provide an array and subscript vector, and then call the function
get_array(Array, vector(i, j))。
Instead, many programming languages provide the following syntax to access array elements Array[i, j].
Similarly, updating array elements can be expressed as
set_array(Array, vetor(i, j), value),
But many programming languages provide the following syntax to update array elements
Array[i, j] := value。
Specifically, syntax sugar refers to the language A component of the language. When the component is removed, it does not affect the function and expression ability of the language. For example, the token a[i] in C language is the syntactic sugar of *(a i).
Popular explanation
It becomes sweeter when sugar is added, but the nature does not change, that is, the code function is the same before adding sugar and after adding sugar.
It tastes better after adding sugar, the code is smoother, and the understanding is more natural
Simply put, syntax sugar is a convenient way of writing.
【Related recommendations: javascript video tutorial, web front-end】
The above is the detailed content of What does es6 syntactic sugar mean?. For more information, please follow other related articles on the PHP Chinese website!

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

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

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

Hot Topics











In ES6, you can use the reverse() method of the array object to achieve array reversal. This method is used to reverse the order of the elements in the array, putting the last element first and the first element last. The syntax "array.reverse()". The reverse() method will modify the original array. If you do not want to modify it, you need to use it with the expansion operator "...", and the syntax is "[...array].reverse()".

async is es7. async and await are new additions to ES7 and are solutions for asynchronous operations; async/await can be said to be syntactic sugar for co modules and generator functions, solving js asynchronous code with clearer semantics. As the name suggests, async means "asynchronous". Async is used to declare that a function is asynchronous; there is a strict rule between async and await. Both cannot be separated from each other, and await can only be written in async functions.

For browser compatibility. As a new specification for JS, ES6 adds a lot of new syntax and API. However, modern browsers do not have high support for the new features of ES6, so ES6 code needs to be converted to ES5 code. In the WeChat web developer tools, babel is used by default to convert the developer's ES6 syntax code into ES5 code that is well supported by all three terminals, helping developers solve development problems caused by different environments; only in the project Just configure and check the "ES6 to ES5" option.

Steps: 1. Convert the two arrays to set types respectively, with the syntax "newA=new Set(a);newB=new Set(b);"; 2. Use has() and filter() to find the difference set, with the syntax " new Set([...newA].filter(x =>!newB.has(x)))", the difference set elements will be included in a set collection and returned; 3. Use Array.from to convert the set into an array Type, syntax "Array.from(collection)".

In es5, you can use the for statement and indexOf() function to achieve array deduplication. The syntax "for(i=0;i<array length;i++){a=newArr.indexOf(arr[i]);if(a== -1){...}}". In es6, you can use the spread operator, Array.from() and Set to remove duplication; you need to first convert the array into a Set object to remove duplication, and then use the spread operator or the Array.from() function to convert the Set object back to an array. Just group.

In es6, the temporary dead zone is a syntax error, which refers to the let and const commands that make the block form a closed scope. Within a code block, before a variable is declared using the let/const command, the variable is unavailable and belongs to the variable's "dead zone" before the variable is declared; this is syntactically called a "temporary dead zone". ES6 stipulates that variable promotion does not occur in temporary dead zones and let and const statements, mainly to reduce runtime errors and prevent the variable from being used before it is declared, resulting in unexpected behavior.

No, require is the modular syntax of the CommonJS specification; and the modular syntax of the es6 specification is import. require is loaded at runtime, and import is loaded at compile time; require can be written anywhere in the code, import can only be written at the top of the file and cannot be used in conditional statements or function scopes; module attributes are introduced only when require is run. Therefore, the performance is relatively low. The properties of the module introduced during import compilation have slightly higher performance.

In ES6, you can use the length attribute of the array object to determine how many items there are in the array, that is, to get the number of elements in the array; this attribute can return the number of elements in the array, just use the "array.length" statement. Returns a value representing the number of elements of the array object, that is, the length value.
