JS Basic knowledge

In order for the browser to run JavaScript, you must first have an HTML page, introduce JavaScript into the HTML page, and then let the browser load the HTML page to execute the JavaScript code.

1. Internal references

JavaScript code can be directly embedded in the Web page of any place. No, but now we usually put the JavaScript code before the "(end tag)." The code included is the JavaScript code, which will be directly controlled by the browser. Line

2. External references

The second way is to put the JavaScript code into a separate JS file, and then in the HTML through <script src= "..." ></script> introduce this file

There are three ways to output:

1. Page Output

document.write ("Hello wolrd");

2 Console output

Console.log ("Hello wolrd");

Console.info ("Hello wolrd");

3. Pop-up window output

Alert ("Hello wolrd"); Prompt ("Hello wolrd");

JS Basic knowledge