@Shawno, actually EX3300 does NOT use IRB CLI syntax, as it does not use ELS CLI (https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/getting-started-els.html). Older EX switches, EX2200/3300/4200, use original CLI with syntax "vlan" while newer switches EX2300/EX3400/EX4300/all QFX5K/10K, EX9200, etc. use ELS CLI with syntax "irb".
L3 for VLAN (or later IRB) is configured under 'interface' stanza. It uses a unit number (can be more than one for multiple IPs) which must be unique and "usually" is assigned using the same number as "vlan-id". This can be expressed as vlan unit X, or vlan.X. This is why in @kparamei reply, he used vlan.25 so that the assigned unit number for the vlan L3, matches the vlan-id.
@kparamei's response is accurate. Hopefully, this explanation may further assist you (and others). ELS CLI is 100% dependant on product family and has nothing to do with SW Release. There is no way to use SW to move from Original VLAN CLI to ELS CLI. The only method to do this is to change the switch hardware model.