JavaScript英文单词汇总「PHP新手收藏」

JavaScript英文单词汇总「PHP新手收藏」

1. Introduction

JavaScript is a popular programming language used for creating dynamic and interactive websites. It is widely used amongst web developers due to its ease of use and flexibility. In this article, we will provide a comprehensive list of JavaScript words commonly used in web development, making it a perfect reference guide for any beginner or experienced JavaScript developer.

2. Data Types

2.1 Primitive Types

JavaScript has six primitive types:

Boolean

Null

Undefined

Number

String

Symbol (new in ES6)

Primitive types are values that have no properties or methods. They are immutable, meaning they cannot be changed, and they are compared by value, not by reference.

2.2 Object Types

In addition to primitive types, JavaScript has object types. Objects are collections of properties, where each property is a key-value pair. Object properties can be accessed using either dot notation or bracket notation. In JavaScript, arrays and functions are also objects.

3. Operators

Operators are special symbols used to perform operations on operands. JavaScript has several types of operators, including:

3.1 Arithmetic Operators

Arithmetic operators are used to perform mathematical operations such as addition, subtraction, multiplication, and division.

var x = 5;
var y = 10;
console.log(x + y); // Output: 15
console.log(y - x); // Output: 5
console.log(x * y); // Output: 50
console.log(y / x); // Output: 2

3.2 Assignment Operators

Assignment operators are used to assign values to variables.

var x = 5;
x += 10; // Equivalent to x = x + 10
console.log(x); // Output: 15

3.3 Comparison Operators

Comparison operators are used to compare two values and return a Boolean value indicating whether the comparison is true or false.

var x = 5;
var y = 10;
console.log(x < y); // Output: true
console.log(x > y); // Output: false
console.log(x == y); // Output: false
console.log(x != y); // Output: true

4. Functions

Functions are a set of statements that perform a specific task. They take one or more arguments as input and return a value. In JavaScript, functions are objects, which means they can be assigned to variables, passed as arguments to other functions, and returned from functions.

4.1 Function Declaration

function hello(name) {
  console.log("Hello, " + name + "!");
}
hello("John"); // Output: Hello, John!

4.2 Function Expression

var hello = function(name) {
  console.log("Hello, " + name + "!");
};
hello("John"); // Output: Hello, John!

5. Events

An event is an action or occurrence that happens in a web page, such as a user clicking a button or scrolling down the page. In JavaScript, you can use events to trigger code execution.

5.1 Event Listeners

Event listeners are functions that are executed in response to an event. They are added to the element that triggers the event using the addEventListener() method.

document.getElementById("myButton").addEventListener("click", function() {
  alert("Button clicked!");
});

5.2 Event Object

The event object contains information about the event that triggered the listener, such as which mouse button was clicked or which key was pressed. It is passed as an argument to the listener function.

document.addEventListener("keydown", function(event) {
  console.log("Key pressed: " + event.key);
});

6. Conclusion

In this article, we have provided a comprehensive list of JavaScript words commonly used in web development. We hope this guide serves as a helpful reference for both beginner and experienced JavaScript developers. Remember to always keep learning and experimenting with new JavaScript concepts and techniques.