encodeURI doesn't escape `equals` - why?

Question

I have an URI like that:

http://client.dev/dap/module/hdfs-web/api/v1.0/clusters/Cluster%201%20-%20CDH4?operation=copy&to=/user/hdfs/year=2016/partial.txt&overwrite=true

I use encodeURI function to escape string. I'm wondering why spaces are encoded with %20 while equals characters are not?

Answer 1

encodeURI encodes a full URI, and URIs can contain = characters. For instance, if a user types in a URI, a first step to resolve it would be to call encodeURI on it.

If on the other hand you are the one constructing the URI, and the input just determines one field (for instance a search query, when given E=mc² you want to resolve https://www.google.com/search?q=E%3Dmc%C2%B2), then you are not encoding a full URI, but a URI component. Use encodeURIComponent for that:

> encodeURIComponent('= ')
'%3D%20'