If not specify all parameters in the function, then what's the default value? (JS syntax related)

cocos2d-x JavaScript
#1

According to the following description of addChild function

addChild(child, zOrder, tag)
“add” logic MUST only be on this method
If a class want’s to extend the ‘addChild’ behaviour it only needs
to override this method
>
Parameters:
{cc.Node} child
{Number} zOrder
{Number} tag

If I don’t specify tag, what’s the default value would be?

#2

its

cc.CCNODE_TAG_INVALID = 1
however, you should not find child by1

if you are wondering about the syntax, here it is

var tempzOrder = (zOrder != null) ? zOrder : child.getZOrder();
var tmptag = (tag != null) ? tag : child.getTag();

which translates to, if z-order and tag is unspecified, it uses the child’s z-order and/or tag.

cc.Node default tag is cc.CCNODE_TAG_INVALID, and default z-order is 0