Get SharePoint list column value using javascript

Below is the function to easily get sharepoint list column value using internal name, its better to get value then using column id.

function getField(fieldType,fieldTitle) {
    var docTags = document.getElementsByTagName(fieldType);
    for (var i=0; i < docTags.length; i++) {
        if (docTags[i].title == fieldTitle) {
            return docTags[i]
        }
    }
}

to get single line text use :

getField('input' , 'Title');

Choice Colum:

 getField('select' , 'col name');

Hide SharePoint list form fields using jQuery/Javascript

Just add jQuery reference and use below lines

Single line/Multi Line

$("input[title$='Col Name']").closest('tr').hide();

Dropdown

$("select[title$='Col Name']").closest('tr').hide();

to show field use below line

$("select[title$='Col Name']").closest('tr').show();

People Picker or any other field

$("nobr:contains('Col Name')").closest('tr').hide();

Readonly text colum:

$("input[title='Col Name']").attr("readonly",true);