isChild（node1，node2）javascript

Question

在javascript中实现以下功能的有效方法

boolean isChild(node1, node2)

where,
node1 = Considered parent node
node2 = Considered child node

function returns true if node2 is a child of node1 else false

Answer 1

function isChild(node1, node2) {
    return node2 && node2.parentNode === node1;
}

DEMO： http://jsfiddle.net/pPaKy/