JS How to insert elements in front of the original element instead of the end

Grammar:

Parent. insertbefore (new element, inserted element);//add A new element before the specified element

parent. insertbefore (new element, parent. children[0]); Insert an element in front of the first element, under IE if the node of the second parameter does not exist, it will be an error, if other browsers, it will be added by default in the form of appendchild, will not error

So when you use it, you need to make another judgment: suppose the new element is oli, and the parent element is Oul

If (oul.children[0]) {

Oul. InsertBefore (oul.children[0]);

}else{

Oul.appendchild (oLi);

}

When adding a tag dynamically, note the notation:

var oa=document.createelement (' a ');

oa.href= ' javascript:; ' ；

Oa.innerhtml= ' link ';

JS How to insert elements in front of the original element instead of the end