Validating part of a number

[Eiolon]

I have a script that queries a database of barcodes.  The barcodes always start with 29971 and have an additional 9 numbers after it.  I need a way to make sure anything that does not start with 29971 gets rejected.  Any ideas?

[Stephen]

Try something like:

 

$_barcode=29971042354455;
if (substr(strval($_barcode),0,5)==="29971")) {
  echo("Correct");
}