# Inserting Elements With the += Operator

Using the += operator, you can insert an XML element at the end of a list of sibling elements. (Note that this operator is equivalent to using the appendChild function described in Functions for Manipulating XML.)

This can be useful when you want to insert a new element into an existing list, as in the following example.

    /* Declare an XML variable with a literal XML value. */
    var xmlEmployees =
        <employees>
            <employee>
                <firstname>John</firstname>
                <lastname>Walton</lastname>
                <age>25</age>
            </employee>
            <employee>
                <firstname>Gladys</firstname>
                <lastname>Cravits</lastname>
                <age>53</age>
            </employee>
    </employees>;

    /* Insert a new node with information about Rob Petrie at the end of the list */
    xmlEmployees..employee[1] +=
            <employee id = "333333333">
                <firstname>Rob</firstname>
                <lastname>Petrie</lastname>
                <age>34</age>
            </employee>;

This operator can't be used in cases where the left operand is an XMLList, as in the following example. This example attempts to insert the new <employee> element at the end of the list by omitting a specific reference to a particular element (as in the preceding example). To insert an element as the last in a list, use the appendChild function.

    /* This causes a run-time error. */
    xmlEmployees.employee +=
            <employee>
                <firstname>Sue</firstname>
                <lastname>Day</lastname>
                <age>32</age>
            </employee>;

Related Topics

appendChild function