Function: firstChild(domElementOrStringMarkupOrCSSSelector, functionConfirm(domElement))

Shorthand: first(domElementOrStringMarkupOrCSSSelector, functionConfirm(domElement))

Description: Returns the first child element.

Returns: domElement, or $A object if chained.

Note: When the second parameter is undefined, firstChild() returns the first child DOM element. When the second parameter is set to a function however, it must return true in order for the current node to be returned. This exists for cases when specific criteria are needed, such as a matching tag name or element type.

Example:

// Return the first child DOM element.
var myElement = $A.firstChild(domElement);

// Return the first child DOM element, but only when specific criteria is confirmed.
var myElement = $A.firstChild(domElement, function(node) {
  if (node.nodeName.toLowerCase() === "h2")
    return true;
});

// Or the same using chaining

// Return the first child DOM element.
var myChain = $A(domElement).firstChild();

// Return the first child DOM element, but only when specific criteria is confirmed.
var myChain = $A(domElement).firstChild(function(node) {
  if (node.nodeName.toLowerCase() === "h2")
    return true;
});

// To return the modified element within a chain, use the "return()" method.

var myElement = myChain.return();