javascript - When to use atob, encodeURIComponent and btoa, decodeURIComponent -

when use atob, encodeuricomponent, btoa, decodeuricomponent. suppose used i.e., atob(encodeuricomponent(...))? if not, when atob&btoa used , when encodeuricomponent&decodeuricomponent used.

btoa() encodes string of binary data in base-64 format. common use of creating data: uri contents of file (e.g. turning jpeg or gif file data: uri incorporate directly page instead of referencing remote file).

atob() performs opposite: given base-64 string, returns binary data.

encodeuricomponent() used perform url-encoding of strings used in uri. converts characters have special meaning in uris % followed hex encoding, e.g. space becomes %20. used when creating url parameters used in redirects or ajax requests, or data sent in xmlhttprequest.send().

decodeuricomponent() performs reverse of encodeuricomponent(), if have "foo%20bar" return "foo bar".

it's pretty rare need use both url-encoding , base-64 same string.