How to access Joomla Admin form field values?

Question

I have been searching for accessing Joomla form field values from admin side and also have found some links but these links couldn't help me.

    <field name="fields" type="hidden" default="ZAIN" />

Here I want to access its value and want to modify its value after accessing.

        <?xml version="1.0" encoding="utf-8"?>
    <form name = 'learning_jform'>
        <fieldset>
            <field name="id" type="hidden" />
            <field name="fields" type="hidden" default="ZAIN" />
            <field
                    name="name"
                    type="text"
                    label="Enter Name:"
                    description="COM_FORMMANAGER_FORMMANAGER_NAME_DESC"
                    size="40"
                    class="inputbox"
                    default=""
                    />
        </fieldset>
        <field name="types" type="list" default="" label="Select Field Types:" description="">
            <option value="text">text</option>
            <option value="email">email</option>
            <option value="password">password</option>
            <option value="textarea">textarea</option>
        </field>
    </form>

Answer 1

Where are you wanting to access the field? In a module? In general, try:

$myField = $params->get('fields', 'ZAIN');