亚洲国产日韩欧美一区二区三区,精品亚洲国产成人av在线,国产99视频精品免视看7,99国产精品久久久久久久成人热,欧美日韩亚洲国产综合乱

Home Web Front-end JS Tutorial Operator Fundamentals

Operator Fundamentals

Oct 23, 2024 am 08:25 AM

Fundamentos de Operadores

The fundamentals of operators in programming are essential for performing mathematical operations, logical comparisons, data manipulation and flow control within a program. Let's learn them using JavaScript?

Main types of operators in JavaScript:

1. Arithmetic Operators

They are used to perform mathematical operations between numbers. These operators include:

  • Addition ( ): Adds two values.
  • Subtraction (-): Subtracts the second value from the first.
  • Multiplication (*): Multiplies two values.
  • Division (/): Divides the first value by the second.
  • Module (%): Returns the remainder of the division between two values.
  • Exponentiation (``)**: Raises the first value to the power of the second.

Example:

let a = 10;
let b = 3;

console.log(a + b);  // Adi??o: 13
console.log(a - b);  // Subtra??o: 7
console.log(a * b);  // Multiplica??o: 30
console.log(a / b);  // Divis?o: 3.333
console.log(a % b);  // Módulo: 1 (resto da divis?o de 10 por 3)
console.log(a ** b); // Exponencia??o: 1000 (10 elevado a 3)

2. Assignment Operators

Assignment operators are used to assign values ??to variables. The most common operator is "=", but there are combinations with arithmetic operators that make the code easier.

  • Assignment (=): Assigns a value to the variable.
  • Assignment with addition ( =): Adds and assigns the result to the variable.
  • Assignment with subtraction (-=): Subtracts and assigns the result to the variable.
  • Assignment with multiplication (*=): Multiplies and assigns the result to the variable.
  • Assignment with division (/=): Divides and assigns the result to the variable.

Example:

let x = 5;
x += 3;  // x = x + 3 -> 8
x -= 2;  // x = x - 2 -> 6
x *= 4;  // x = x * 4 -> 24
x /= 2;  // x = x / 2 -> 12

console.log(x);  // Resultado final: 12

3. Comparison Operators

These operators compare two values ??and return a boolean value (true or false). They are widely used in control structures, such as if, and while.

  • Equality (==): Checks if the values ??are equal, without checking the type.
  • Identity (===): Checks if the values ??and types are exactly the same.
  • Different (!=): Checks if the values ??are different.
  • Strict difference (!==): Checks if values ??and types are different.
  • Greater than (>): Checks if the value on the left is greater.
  • Less than (<): Checks if the value on the left is smaller.
  • Greater or equal (>=): Checks if the value on the left is greater or equal.
  • Less than or equal (<=): Checks if the value on the left is less than or equal.

Example:

let a = 10;
let b = 3;

console.log(a + b);  // Adi??o: 13
console.log(a - b);  // Subtra??o: 7
console.log(a * b);  // Multiplica??o: 30
console.log(a / b);  // Divis?o: 3.333
console.log(a % b);  // Módulo: 1 (resto da divis?o de 10 por 3)
console.log(a ** b); // Exponencia??o: 1000 (10 elevado a 3)

4. Logical Operators

Logical operators are used to combine Boolean expressions (true or false) and are essential for flow control.

  • AND ( && ): Returns true if both expressions are true.
  • OR ( || ): Returns true if at least one of the expressions is true.
  • NOT ( ! ): Inverts the Boolean value of an expression.

Example:

let x = 5;
x += 3;  // x = x + 3 -> 8
x -= 2;  // x = x - 2 -> 6
x *= 4;  // x = x * 4 -> 24
x /= 2;  // x = x / 2 -> 12

console.log(x);  // Resultado final: 12




5. Unary Operators

These operators work with just one operand and can modify or return the value of a variable.

  • Increment ( ): Adds 1 to the variable value.
  • Decrement (--): Subtract 1 from the variable value.

Example:

let num1 = 10;
let num2 = '10';

console.log(num1 == num2);   // true (só compara o valor)
console.log(num1 === num2);  // false (compara valor e tipo)
console.log(num1 != num2);   // false (valores s?o iguais)
console.log(num1 !== num2);  // true (tipos s?o diferentes)
console.log(num1 > 5);       // true
console.log(num1 <= 10);     // true

It is important to remember that the order of these operators influences the behavior of the variable. There are two ways to use them:

  • Prefixed x or --x: Use the current value of the variable in the expression and then increment/decrement it.
  • Posfixed x or x--: Increments/decrements the value before using it in the expression (as exemplified previously).

Find out more by clicking here

6. Ternary Operators

The ternary operator is a simplified form of an if to assign values ??based on a condition. Is your structure a condition? value_if_true : value_if_false.

Example:

let a = true;
let b = false;

console.log(a && b);  // false (AND: ambos devem ser verdadeiros)
console.log(a || b);  // true (OR: ao menos um deve ser verdadeiro)
console.log(!a);      // false (NOT: inverte o valor de 'a')

Learn more about Ternary Operators here

7. String Concatenate Operator ( )

The addition operator ( ) can also be used to concatenate strings (join texts).

Example:

let a = 10;
let b = 3;

console.log(a + b);  // Adi??o: 13
console.log(a - b);  // Subtra??o: 7
console.log(a * b);  // Multiplica??o: 30
console.log(a / b);  // Divis?o: 3.333
console.log(a % b);  // Módulo: 1 (resto da divis?o de 10 por 3)
console.log(a ** b); // Exponencia??o: 1000 (10 elevado a 3)

8. Bitwise Operators (Bitwise)

These operators perform bit-level operations (0s and 1s), generally used in low-level programming, such as hardware operations. It is not common to use these types of operators.

  • AND Bit by Bit (&)
  • OR Bit by Bit (|)
  • XOR Bit by Bit (^)
  • NOT Bit by Bit (~)
  • Left shift (<<)
  • Right shift (>>)

Example:

let x = 5;
x += 3;  // x = x + 3 -> 8
x -= 2;  // x = x - 2 -> 6
x *= 4;  // x = x * 4 -> 24
x /= 2;  // x = x / 2 -> 12

console.log(x);  // Resultado final: 12

Understanding how Operators work is fundamental to building programs that perform calculations, comparisons and control the flow of code efficiently.

The above is the detailed content of Operator Fundamentals. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undress AI Tool

Undress AI Tool

Undress images for free

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

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

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How does garbage collection work in JavaScript? How does garbage collection work in JavaScript? Jul 04, 2025 am 12:42 AM

JavaScript's garbage collection mechanism automatically manages memory through a tag-clearing algorithm to reduce the risk of memory leakage. The engine traverses and marks the active object from the root object, and unmarked is treated as garbage and cleared. For example, when the object is no longer referenced (such as setting the variable to null), it will be released in the next round of recycling. Common causes of memory leaks include: ① Uncleared timers or event listeners; ② References to external variables in closures; ③ Global variables continue to hold a large amount of data. The V8 engine optimizes recycling efficiency through strategies such as generational recycling, incremental marking, parallel/concurrent recycling, and reduces the main thread blocking time. During development, unnecessary global references should be avoided and object associations should be promptly decorated to improve performance and stability.

How to make an HTTP request in Node.js? How to make an HTTP request in Node.js? Jul 13, 2025 am 02:18 AM

There are three common ways to initiate HTTP requests in Node.js: use built-in modules, axios, and node-fetch. 1. Use the built-in http/https module without dependencies, which is suitable for basic scenarios, but requires manual processing of data stitching and error monitoring, such as using https.get() to obtain data or send POST requests through .write(); 2.axios is a third-party library based on Promise. It has concise syntax and powerful functions, supports async/await, automatic JSON conversion, interceptor, etc. It is recommended to simplify asynchronous request operations; 3.node-fetch provides a style similar to browser fetch, based on Promise and simple syntax

JavaScript Data Types: Primitive vs Reference JavaScript Data Types: Primitive vs Reference Jul 13, 2025 am 02:43 AM

JavaScript data types are divided into primitive types and reference types. Primitive types include string, number, boolean, null, undefined, and symbol. The values are immutable and copies are copied when assigning values, so they do not affect each other; reference types such as objects, arrays and functions store memory addresses, and variables pointing to the same object will affect each other. Typeof and instanceof can be used to determine types, but pay attention to the historical issues of typeofnull. Understanding these two types of differences can help write more stable and reliable code.

JavaScript time object, someone builds an eactexe, faster website on Google Chrome, etc. JavaScript time object, someone builds an eactexe, faster website on Google Chrome, etc. Jul 08, 2025 pm 02:27 PM

Hello, JavaScript developers! Welcome to this week's JavaScript news! This week we will focus on: Oracle's trademark dispute with Deno, new JavaScript time objects are supported by browsers, Google Chrome updates, and some powerful developer tools. Let's get started! Oracle's trademark dispute with Deno Oracle's attempt to register a "JavaScript" trademark has caused controversy. Ryan Dahl, the creator of Node.js and Deno, has filed a petition to cancel the trademark, and he believes that JavaScript is an open standard and should not be used by Oracle

React vs Angular vs Vue: which js framework is best? React vs Angular vs Vue: which js framework is best? Jul 05, 2025 am 02:24 AM

Which JavaScript framework is the best choice? The answer is to choose the most suitable one according to your needs. 1.React is flexible and free, suitable for medium and large projects that require high customization and team architecture capabilities; 2. Angular provides complete solutions, suitable for enterprise-level applications and long-term maintenance; 3. Vue is easy to use, suitable for small and medium-sized projects or rapid development. In addition, whether there is an existing technology stack, team size, project life cycle and whether SSR is needed are also important factors in choosing a framework. In short, there is no absolutely the best framework, the best choice is the one that suits your needs.

Understanding Immediately Invoked Function Expressions (IIFE) in JavaScript Understanding Immediately Invoked Function Expressions (IIFE) in JavaScript Jul 04, 2025 am 02:42 AM

IIFE (ImmediatelyInvokedFunctionExpression) is a function expression executed immediately after definition, used to isolate variables and avoid contaminating global scope. It is called by wrapping the function in parentheses to make it an expression and a pair of brackets immediately followed by it, such as (function(){/code/})();. Its core uses include: 1. Avoid variable conflicts and prevent duplication of naming between multiple scripts; 2. Create a private scope to make the internal variables invisible; 3. Modular code to facilitate initialization without exposing too many variables. Common writing methods include versions passed with parameters and versions of ES6 arrow function, but note that expressions and ties must be used.

Handling Promises: Chaining, Error Handling, and Promise Combinators in JavaScript Handling Promises: Chaining, Error Handling, and Promise Combinators in JavaScript Jul 08, 2025 am 02:40 AM

Promise is the core mechanism for handling asynchronous operations in JavaScript. Understanding chain calls, error handling and combiners is the key to mastering their applications. 1. The chain call returns a new Promise through .then() to realize asynchronous process concatenation. Each .then() receives the previous result and can return a value or a Promise; 2. Error handling should use .catch() to catch exceptions to avoid silent failures, and can return the default value in catch to continue the process; 3. Combinators such as Promise.all() (successfully successful only after all success), Promise.race() (the first completion is returned) and Promise.allSettled() (waiting for all completions)

What is the cache API and how is it used with Service Workers? What is the cache API and how is it used with Service Workers? Jul 08, 2025 am 02:43 AM

CacheAPI is a tool provided by the browser to cache network requests, which is often used in conjunction with ServiceWorker to improve website performance and offline experience. 1. It allows developers to manually store resources such as scripts, style sheets, pictures, etc.; 2. It can match cache responses according to requests; 3. It supports deleting specific caches or clearing the entire cache; 4. It can implement cache priority or network priority strategies through ServiceWorker listening to fetch events; 5. It is often used for offline support, speed up repeated access speed, preloading key resources and background update content; 6. When using it, you need to pay attention to cache version control, storage restrictions and the difference from HTTP caching mechanism.

See all articles