JavaScript basic syntax

Create the 1~4 section folder before creating the HTML file:

Section One: How JavaScript is introduced

First introduce the internal introduction of two methods: JS script in

JS script must be wrapped in <srcipt></script> inside: first included in head

Operation Result:

Contained inside the body:

Operation Result:

The next step is the external introduction method:

Create JS file in SEC01: Project right-new file

Inside write:

Next introduce Myjs.js:

Operation Result:

If garbled, the property's character property may be incorrect:

Can join: CharSet and properties of the encoding like, otherwise garbled. It is best to unify into UTF-8, garbled and modified code .

2. JavaScript Comments:

Single-line Comment://

Multiline Comment:/* */

3. JavaScript variables:

JavaScript is a weak language type and uses var to define variables (any).

Description: JS has a garbage collection mechanism, a from 1 into a string, then 1 will be destroyed immediately.

There is no type of strict meaning.

Define variables and assign values directly below:

4. JavaScript Basic Data type:

Strings Support "", "" (English input state) both can.

Next write the value, String, Boolean type:

Results:

Next comes the 2 special:

1, Undefined:

2. Empty the variable:

JavaScript basic syntax