Ajax2-php (28), ajax2php28

Ajax2-php (28), ajax2php28

8. Use post to transmit data

L xmlhttp. open ("post", "action. php ");

L xmlhttp. setRequestHeader ("Content-Type", "application/x-www-form-urlencoded ");

L xmlhttp. send (data );

 

1. What are the differences between get and post requests?

The size of transferred data is different:

Get: 2 k

Post: original restriction

 

Different data transmission methods:

Get: After url

Post: After blank rows

 

Different data transmission formats:

Get: text string

Post: text string, binary

Get request:

Post request:

Php code:

 

The packet capture result is as follows:

We can see that this http Request

1) post request

2) use the content-type Request Header

3) The parameter is placed behind the blank line.

Modify the php code in the above question and immediately return the latest results.

Post requests do not cause cache problems.

Example:

Use Ajax to input data

9. xml application in ajax

In ajax, we can use responseText for simple returned data.

For large batches of complex data, xml or json technology is required.

Corresponding parsing code:

L var xml = xmlHttp. responseXML;

L node = xml. getElementByTagName ("TagName ");

L node [0]. childNodes [0]. nodeValue;