Javascript DIV scroll to bottom by class name not working

Question

I have a div which with long content and that is why the scrollbar is coming. I want when user click on a button. Then, the div scroll bar goes to end of the content. I tried this way but no luck.

I want to achieve this without using jQuery.

<div id="test" class="module-content">
<h3>
Welcome all!
</h3>
Lorizzle ipsizzle i saw beyonces tizzles and my pizzle went crizzle go to hizzle amizzle, fo adipiscing crunk. sapizzle velizzle, boom shackalack volutpizzle, suscipizzle quis, gravida vel, gizzle. Pellentesque bizzle bow wow wow. Sheezy bow wow wow. Phat at my shizz dapibus turpizzle tempizzle things. Away pellentesque nibh izzle bow wow wow. Hizzle izzle that's the shizzle. Fo shizzle eleifend rhoncizzle nisi. Hizzle hac owned platea dictumst. Bow wow wow dapibizzle. Own yo' tellus ma nizzle, pretizzle eu, fizzle fo shizzle my nizzle, eleifend sheezy, nunc. Da bomb brizzle. Gizzle sempizzle velit sizzle fo shizzle.
<br /><br />
Etiam rizzle urna nisl. Break it down quizzle izzle. Maecenizzle my shizz, ipsizzle malesuada shizzlin dizzle, the bizzle purizzle euismizzle check it out, et sure metus mammasay mammasa mamma oo sa et da bomb. Vivamus break it down, tortizzle izzle varius fizzle, nibh fo shizzle ultricizzle go to hizzle, izzle luctus leo fizzle in dolizzle. Mauris things, orci shut the shizzle up volutpizzle away, fo yo mamma luctizzle daahng dawg, izzle bibendum enim sheezy izzle nisl. Nullizzle fo shizzle velizzle shit orci shizzlin dizzle yo mamma. Fo shizzle daahng dawg own yo'. Curabitizzle i'm in the shizzle sheezy vel pede dope facilisizzle. Maecenizzle sapien nulla, boofron crunk, away pot, egestizzle a, eros. Its fo rizzle vitae turpizzle quis nibh bibendizzle fo shizzle. Nizzle yippiyo consectetizzle shizznit. Mah nizzle ghetto break it down. Nunc fo shizzle owned at go to hizzle pretizzle phat. Black uhuh ... yih! lacizzle check it out that's the shizzle my shizz ultricizzle. Shizznit nisl. Mah nizzle izzle urna. Integizzle cool ipsizzle in for sure. Owned sure yo mamma.
<br /><br />
Integizzle mammasay mammasa mamma oo sa metizzle izzle arcu interdum dang. Fo shizzle posuere. Sed funky fresh ante. Dizzle hizzle pede, bizzle ac, dizzle izzle, yo mamma quizzle, black. Vestibulizzle feugizzle. I saw beyonces tizzles and my pizzle went crizzle vehicula ultricizzle leo. Fo uhuh ... yih!, orci a suscipizzle rizzle, enim lacus mofo things, pizzle nizzle dizzle my shizz nizzle da bomb. Maecenizzle mofo shit fo shizzle my nizzle. Quisque dope mauris, nonummy doggy, malesuada izzle, brizzle varizzle, ass. In check it out, ligula cool pretizzle hendrerit, velizzle rizzle posuere nisl, a ghetto justo nizzle sizzle amet the bizzle. Aliquam izzle mah nizzle check it out cool bizzle crunk. Quisque aliquizzle tempizzle cool. Nam vehicula hendrerit maurizzle. Owned dawg. Crizzle pimpin' yo a mi. Stuff pimpin'. In hac its fo rizzle platea dictumst. Crizzle shiz check out this diam the bizzle tellivizzle. Get down get down erizzle ante, pulvinar pizzle, fringilla a, consectetizzle yo, nisl. Black vel nibh ut tempus fringilla.
<br /><br />
In sheezy da bomb nizzle cool. Yo ullamcorpizzle. Etiam mah nizzle. Ma nizzle izzle mi a check it out imperdizzle mofo. Dizzle vel ipsizzle. Sizzle iaculizzle shit break it down dope. Praesent a fo shizzle my nizzle vitae urna euismod fo shizzle my nizzle. Uhuh ... yih! nizzle risus. Vivamus go to hizzle things dang felis. Morbi dizzle ma nizzle. Etizzle eu dui ghetto magna lobortizzle. Morbi , ma nizzle nizzle crunk porta, fizzle fo shit nunc, mah nizzle boofron izzle dolor sizzle amizzle est. Things turpizzle. Vestibulizzle ante ipsizzle primis izzle faucibus orci luctus et my shizz posuere cubilia Stuff; Yo mamma vehicula, justo laorizzle bling bling fo shizzle, risus lorizzle gravida nunc, shizzlin dizzle fermentum urna metizzle quis nibh. That's the shizzle pretizzle erizzle izzle fizzle. Phasellizzle accumsan. Its fo rizzle fo shizzle fizzle penatibizzle for sure away dizzle break it down hizzle, go to hizzle ridiculus mus. Pimpin' nizzle massa shit quizzle ultrices congue. Donizzle non mi.<br /><br />

<h3>
End of this epic shizzle manizzle story yo.
</h3>
</div>

<button onClick="Scroll()">
    Scroll it !!
</button>

function Scroll() {
    var obj = document.getElementsByClassName('module-content');
    obj.scrollTop = obj.scrollHeight;
}

Answer 1

getElementsByClassName returns HTMLCollection (multiple matched elements)

Try accessing like this

function Scroll() {
    const allMatchedElements = document.getElementsByClassName('module-content');
    const moduleContent = allMatchedElements[0] //first matched element
    moduleContent.scrollTop = moduleContent.scrollHeight;
}

Note: This will only work if your element has scrollbar, If it is a browser scrollbar then you can scroll like this.

document.documentElement.scrollTop = document.documentElement.scrollHeight

function Scroll() {
    const allMatchedElements = document.getElementsByClassName('module-content');
    const moduleContent = allMatchedElements[0] //first matched element
    moduleContent.scrollTop = moduleContent.scrollHeight;
}

.module-content {
  max-height: 160px;
  overflow: auto;
}

<button onClick="Scroll()">
    Scroll it !!
</button>

<div id="test" class="module-content">
  <h3>
    Welcome all!
  </h3>
  Lorizzle ipsizzle i saw beyonces tizzles and my pizzle went crizzle go to hizzle amizzle, fo adipiscing crunk. sapizzle velizzle, boom shackalack volutpizzle, suscipizzle quis, gravida vel, gizzle. Pellentesque bizzle bow wow wow. Sheezy bow wow wow.
  Phat at my shizz dapibus turpizzle tempizzle things. Away pellentesque nibh izzle bow wow wow. Hizzle izzle that's the shizzle. Fo shizzle eleifend rhoncizzle nisi. Hizzle hac owned platea dictumst. Bow wow wow dapibizzle. Own yo' tellus ma nizzle,
  pretizzle eu, fizzle fo shizzle my nizzle, eleifend sheezy, nunc. Da bomb brizzle. Gizzle sempizzle velit sizzle fo shizzle.
  <br /><br /> Etiam rizzle urna nisl. Break it down quizzle izzle. Maecenizzle my shizz, ipsizzle malesuada shizzlin dizzle, the bizzle purizzle euismizzle check it out, et sure metus mammasay mammasa mamma oo sa et da bomb. Vivamus break it down, tortizzle
  izzle varius fizzle, nibh fo shizzle ultricizzle go to hizzle, izzle luctus leo fizzle in dolizzle. Mauris things, orci shut the shizzle up volutpizzle away, fo yo mamma luctizzle daahng dawg, izzle bibendum enim sheezy izzle nisl. Nullizzle fo shizzle
  velizzle shit orci shizzlin dizzle yo mamma. Fo shizzle daahng dawg own yo'. Curabitizzle i'm in the shizzle sheezy vel pede dope facilisizzle. Maecenizzle sapien nulla, boofron crunk, away pot, egestizzle a, eros. Its fo rizzle vitae turpizzle quis
  nibh bibendizzle fo shizzle. Nizzle yippiyo consectetizzle shizznit. Mah nizzle ghetto break it down. Nunc fo shizzle owned at go to hizzle pretizzle phat. Black uhuh ... yih! lacizzle check it out that's the shizzle my shizz ultricizzle. Shizznit nisl.
  Mah nizzle izzle urna. Integizzle cool ipsizzle in for sure. Owned sure yo mamma.
  <br /><br /> Integizzle mammasay mammasa mamma oo sa metizzle izzle arcu interdum dang. Fo shizzle posuere. Sed funky fresh ante. Dizzle hizzle pede, bizzle ac, dizzle izzle, yo mamma quizzle, black. Vestibulizzle feugizzle. I saw beyonces tizzles and
  my pizzle went crizzle vehicula ultricizzle leo. Fo uhuh ... yih!, orci a suscipizzle rizzle, enim lacus mofo things, pizzle nizzle dizzle my shizz nizzle da bomb. Maecenizzle mofo shit fo shizzle my nizzle. Quisque dope mauris, nonummy doggy, malesuada
  izzle, brizzle varizzle, ass. In check it out, ligula cool pretizzle hendrerit, velizzle rizzle posuere nisl, a ghetto justo nizzle sizzle amet the bizzle. Aliquam izzle mah nizzle check it out cool bizzle crunk. Quisque aliquizzle tempizzle cool. Nam
  vehicula hendrerit maurizzle. Owned dawg. Crizzle pimpin' yo a mi. Stuff pimpin'. In hac its fo rizzle platea dictumst. Crizzle shiz check out this diam the bizzle tellivizzle. Get down get down erizzle ante, pulvinar pizzle, fringilla a, consectetizzle
  yo, nisl. Black vel nibh ut tempus fringilla.
  <br /><br /> In sheezy da bomb nizzle cool. Yo ullamcorpizzle. Etiam mah nizzle. Ma nizzle izzle mi a check it out imperdizzle mofo. Dizzle vel ipsizzle. Sizzle iaculizzle shit break it down dope. Praesent a fo shizzle my nizzle vitae urna euismod fo
  shizzle my nizzle. Uhuh ... yih! nizzle risus. Vivamus go to hizzle things dang felis. Morbi dizzle ma nizzle. Etizzle eu dui ghetto magna lobortizzle. Morbi , ma nizzle nizzle crunk porta, fizzle fo shit nunc, mah nizzle boofron izzle dolor sizzle
  amizzle est. Things turpizzle. Vestibulizzle ante ipsizzle primis izzle faucibus orci luctus et my shizz posuere cubilia Stuff; Yo mamma vehicula, justo laorizzle bling bling fo shizzle, risus lorizzle gravida nunc, shizzlin dizzle fermentum urna metizzle
  quis nibh. That's the shizzle pretizzle erizzle izzle fizzle. Phasellizzle accumsan. Its fo rizzle fo shizzle fizzle penatibizzle for sure away dizzle break it down hizzle, go to hizzle ridiculus mus. Pimpin' nizzle massa shit quizzle ultrices congue.
  Donizzle non mi.<br /><br />

  <h3>
    End of this epic shizzle manizzle story yo.
  </h3>
</div>

Answer 2

You don't actually need javascript. A simple link will do. You can also do it with javascript, but I see no reason to in this case.

This would work:

<div id="test">
    Bla bla bla
</div>

<br />

<a href="#test"></a>

If you really wanted to do it with javascript it'd be something like:

document.getElementById("test").scrollIntoView(true);

Change true to false if you don't want to align by the top, but align by the bottom instead.