Terraform: referencing resources created using a map of objects variable

I am a bit new to Terraform and learning. I have the following defined in my varaibles.tf as a map of objects, which will allow me to configure multiple subnets (currently only 1):

variable "subnets" {
  type        = map(object({name=string, cidr=string, az=string, public=bool}))
  default     = {
    "public_subnet" = {
       name="public",
       cidr="10.123.1.0/24",
       az="us-east-1a",
       public=true
   }
}

In main.tf i have the following:

resource "aws_subnet" "subnets" {
  for_each                = var.subnets
  vpc_id                  = aws_vpc.vpc.id
  cidr_block              = each.value.cidr
  availability_zone       = each.value.az
  map_public_ip_on_launch = each.value.public 
  
  tags = {
    Name = "${each.value.name}_subnet"
  }
}

Now my questions are how would i code the aws_route_table_association and aws_instance to make use of a specific subnet from my varaible map?
Normally if i didnt have a map i would do something like this:

resource "aws_route_table_association" "public_rta" {
  subnet_id      = aws_subnet.subnet.id
  route_table_id = aws_route_table.public_rt.id
}

Im not sure how to references a subnet’s id created in a loop in this case.

>Solution :

For this to work you would have to use for_each with the route table association resource as well (or reference different keys). In the scenario you want all your subnets attached to the same route table, you can use resource chaining with for_each in this case:

resource "aws_subnet" "subnets" {
  for_each                = var.subnets
  vpc_id                  = aws_vpc.vpc.id
  cidr_block              = each.value.cidr
  availability_zone       = each.value.az
  map_public_ip_on_launch = each.value.public 
  tags = {
    Name = "${each.value.name}_subnet"
  }

resource "aws_route_table_association" "public_rta" {
  for_each       = aws_subnet.subnets
  subnet_id      = each.value.id
  route_table_id = aws_route_table.public_rt.id
}