javascript why get only first child code example

Example 1: first child element javascript

Both these will give you the first child node:

console.log(parentElement.firstChild); // or
console.log(parentElement.childNodes[0]);

If you need the first child that is an element node then use:

console.log(parentElement.children[0]);

Example 2: how to add first child using js

var eElement; // some E DOM instance
var newFirstElement; //element which should be first in E

eElement.insertBefore(newFirstElement, eElement.firstChild);