Get a field's internal name from a GlideRecord

The getFields() method returns a GlideElementCollection that must be iterated with hasNext() and next() — it's not a JavaScript array despite looking like one. This catches developers who try forEach() or array methods. The collection only populates after the GlideRecord executes a query, so you need at least one record to see the full field structure — empty tables return empty field collections even though the table definition exists.

When to use this

• Building dynamic integration mappings that need to discover available fields at runtime
• Creating debugging utilities that inspect record structure and field values
• Writing migration scripts that need to copy data between tables with different schemas
• Auditing customizations by comparing field lists between instances

When NOT to use this

• Don't use this in client scripts — the GlideElementCollection API doesn't exist client-side. Use g_form.getTableName() and GlideAjax instead
• Don't iterate fields inside a loop over records — you'll get the same field list repeatedly. Cache the field structure outside the record loop
• Don't use this for table schema analysis — use the sys_dictionary table directly for complete metadata including inactive fields
• Don't use this in performance-critical paths — field iteration is expensive. Pre-calculate and cache field lists when possible

Key behaviors and gotchas

• Extended field names contain dots (e.g., caller_id.name) and may not be writable depending on the reference field's access controls
• The collection only includes fields visible to the current user's ACLs — two users may see different field lists for the same table
• Field order in the collection doesn't match form section order — it reflects the underlying table schema order
• Empty tables return empty field collections even though the table definition exists — you need at least one record
• The getED().getInternalType() method returns the actual field type (e.g., reference, choice) not the JavaScript type
• Domain separation affects field visibility — fields may be hidden based on the record's domain and your domain access