How to set pre-defined "Quantity" in a Catalog item through script?

[Puja7]

How to set quantity as "2" for a particular catalog item.

g_form.setValue("quantity",2) = this is not working 

[Saurav11]

Hello,

If you are using onload client script please use below:-

function onLoad() {
var number=5;
g_cart.setQuantity(number);

}

Please mark answer correct/helpful based on impact.

[Puja7]

This code is not working on portal.

Please suggest me

[Puja7]

I have tried your code but this is not working as well.

this below error is showing 

[Saurav11 · Accepted solution]

With the above code it will work in the Native Ui, for service portal you may have to do DOM manipulation