Format strings in Terraform

variable "elbs" {
  description = "ELB names on which to create the alarm"
  type        = list(string)
  default     = ["elb1", "elb2", "elb3"]
}

resource "aws_cloudwatch_metric_alarm" "healthy_host_count" {
  count = length(var.elbs)
  alarm_name                = format("%s-%s","healthy_host_count", var.elbs[count.index])
  alarm_description         = format("%s-%s","healthy_host_count", var.elbs[count.index])
...
  dimensions = {
    LoadBalancerName = var.elbs[count.index]
  }
}
This will create 3 AWS CloudWatch alarms with names/descriptions: healthy_host_count-elb1, healthy_host_count-elb2 and healthy_host_count-elb3.