Error Code BCE0034 expressions in statement must only be executed for their side-effects'

Okay I am trying To access the children of a gameobject and look in a Component to get a variable. That works fine. But I want to change the variable thats in the child object.

Here is the Code. By the way Item.itemId and Item.amount are variables in a class. They are both ints.

for (var child : Transform in transform)

{
	if(child.GetComponent(InventoryObject).Item.itemId == 1002)
	{
		child.GetComponent(InventoryObject).Item.amount == 20;
	}
}

And then I get the error code BCE0034. Anyone got any ideas?

if(child.GetComponent(InventoryObject).Item.itemId == 1002)
{
child.GetComponent(InventoryObject).Item.amount = 20; // Remove the second ‘=’
}

You have an equality where you should have an assignment in line 4.