Get fields using Javascript Client Object Model

Using the Javascript Client Object Model, you can get values from a listitem. 

How to use the JSOM is described here Code Project

Title – SP.ListItem.get_item(‘Title‘);

ID – SP.ListItem.get_id();

Url -SP.ListItem.get_item(‘urlfieldname‘).get_url()

Description – SP.ListItem.get_item(‘descriptionfieldname‘).get_description();

Current Version – SP.ListItem.get_item(“_UIVersionString“);

Lookup field – SP.ListItem.get_item(‘LookupFieldName’).get_lookupValue(); // or get_lookupID();

Created By – SP.ListItem.get_item(“Author“).get_lookupValue();

Modified by – SP.ListItem.get_item(“Editor“).get_lookupValue();

Choice Field – SP.ListItem.get_item(‘ChoiceFieldName‘);

Created Date – SP.ListItem.get_item(“Created“);

Modified Date – SP.ListItem.get_item(“Modified“); -> case sensitive does not work with ‘modified’

File  – SP.ListItem.get_file();

File Versions -  File.get_versions();.

Content Type – SP.ListItem.get_contentType();

Parent List – SP.ListItem.get_parentList();

Note:  (‘LookupFieldName’).get_lookupValue() sometimes returns an array of data, especially when your lookup allows multiple values.
In that case you will need to iterate the array and get each value individually.

 SP.ListItem.get_item(‘LookupFieldName’)[0].get_lookupValue(); - this will get the first item in the array.

For Arrays:


       for(var i = 0; i < oListItem.get_item("LookupFieldName").length; i++)
{
     alert(oListItem.get_item("LookupFieldName")[i].get_lookupId()); // or get_lookupValue()
}