When are you supposed to use escape instead of encodeURI / encodeURIComponent?

Question

When encoding a query string to be sent to a web server - when do you use escape() and when do you use encodeURI() or encodeURIComponent()

Answer 1

Just try encodeURI() and encodeURIComponent() yourself...

console.log(encodeURIComponent('@#$%^&*'));

Input: @#$%^&*. Output: %40%23%24%25%5E%26*. So, wait, what happened to *? Why wasn't this converted? It could definitely cause problems if you tried to do linux command "$string". TLDR: You actually want fixedEncodeURIComponent() and fixedEncodeURI(). Long-story...

When to use encodeURI()? Never. encodeURI() fails to adhere to RFC3986 with regard to bracket-encoding. Use fixedEncodeURI(), as defined and further explained at the MDN encodeURI() Documentation...

function fixedEncodeURI(str) { return encodeURI(str).replace(/%5B/g, '[').replace(/%5D/g, ']'); }

When to use encodeURIComponent()? Never. encodeURIComponent() fails to adhere to RFC3986 with regard to encoding: !'()*. Use fixedEncodeURIComponent(), as defined and further explained at the MDN encodeURIComponent() Documentation...

function fixedEncodeURIComponent(str) { return encodeURIComponent(str).replace(/[!'()*]/g, function(c) { return '%' + c.charCodeAt(0).toString(16); }); }

Then you can use fixedEncodeURI() to encode a single URL piece, whereas fixedEncodeURIComponent() will encode URL pieces and connectors; or, simply, fixedEncodeURI() will not encode +@?=:#;,$& (as & and + are common URL operators), but fixedEncodeURIComponent() will.