如何使用纯javascript在DIV中获取所有id

Question

I want to get every single ID of every element inside of a Div at once, and change all of their class names. Like:

<div id = "container">
    <div id = "alot"></div>
    <div id = "of"></div>
    <div id = "random"></div>
    <div id = "ids"></div>
</div>

<script>
    var everyId = //all of the ids in #container. but how ?
    document.getElementById( everyId ).className = "anything";
</script>

I've seen solutions using libraries but Is this possible with pure Javascript?

Answer 1

Try something like this:

var ids = [];
var children = document.getElementById("container").children; //get container element children.
for (var i = 0, len = children.length ; i < len; i++) {
    children[i].className = 'new-class'; //change child class name.
    ids.push(children[i].id); //get child id.
}

console.log(ids);

Answer 2

Leverage document.querySelectorAll() and a loop to achieve what you're looking for:

var everyChild = document.querySelectorAll("#container div");
for (var i = 0; i<everyChild.length; i++) {
    everyChild[i].classList.add("anything");
}

JSFiddle

Answer 3

You can use querySelectorAll for the Child elements within the specified parent:

var a = document.querySelectorAll('#container > div'); // get all children within container
console.log(a);
for (var i = 0; i<a.length; i++){ // loop over the elements
    console.log(a[i].id);  //  get the ids
    a[i].className = 'newClass';  // change the class names
}

Answer 4

You can leverage querySelectorAll to provide a selector to fetch the elements you are interested in.

var c = document.querySelectorAll("#container > div");
console.log(c);  // array of all children div below #container