Error After Executing Terraform Plan

[andreprawira]

In your video at 19:38 when you created a key pair manually, i did the same too (my naming convention is following yours), and when i execute terraform plan afterwards, i'd get this error:

Error: Call to unknown function

  on .terraform\modules\vpc\main.tf line 288, in resource "aws_subnet" "public":
 288:   availability_zone               = length(regexall("^[a-z]{2}-", element(var.azs, count.index))) > 0 ? element(var.azs, count.index) : null

There is no function named "regexall".

Anyone know whats going on?