Did Homo Erectus walk upright

Java

yes they did the Cro-Magnons walked upright as long with the homo habilis, neanderthals, ((pecking man and Java man.) homo erectus)

answer 2 The upright stance was probably acquired while in the tree-dwelling phase of development. [side comment Chimps are not purely vegetarian!]

When the apes left the forest; and that was not necessarily a sudden event; the upright stance still held advantage of allowing the animal to see further.

This was more advantage than faster running which is a quadruped feature.