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() :

Use escape:

escape("% +&=");

OR

use encodeURI() / encodeURIComponent()

encodeURI("http://www.google.com?var1=value1&var2=value2");

encodeURIComponent("var1=value1&var2=value2");

---

escape()

Special characters are encoded with the exception of: @*_+-./

The hexadecimal form for characters, whose code unit value is 0xFF or less, is a two-digit escape sequence: %xx. For characters with a greater code unit, the four-digit format %uxxxx is used.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/escape

encodeURI()

Use encodeURI when you want a working URL. Make this call:

encodeURI("http://www.example.org/a file with spaces.html")

to get:

http://www.example.org/a%20file%20with%20spaces.html

Don't call encodeURIComponent since it would destroy the URL and return

http%3A%2F%2Fwww.example.org%2Fa%20file%20with%20spaces.html

encodeURIComponent()

Use encodeURIComponent when you want to encode the value of a URL parameter.

var p1 = encodeURIComponent("http://example.org/?a=12&b=55")

Then you may create the URL you need:

var url = "http://example.net/?param1=" + p1 + "&param2=99";

And you will get this complete URL:

http://example.net/?param1=http%3A%2F%2Fexample.org%2F%Ffa%3D12%26b%3D55&param2=99

Note that encodeURIComponent does not escape the ' character. A common bug is to use it to create html attributes such as href='MyUrl' , which could suffer an injection bug. If you are constructing html from strings, either use " instead of ' for attribute quotes, or add an extra layer of encoding ( ' can be encoded as %27).

For more information on this type of encoding you can check: http://en.wikipedia.org/wiki/Percent-encoding

---

The difference between encodeURI() and encodeURIComponent() are exactly 11 characters encoded by encodeURIComponent but not by encodeURI:

I generated this table easily with console.table in Google Chrome with this code:

var arr = [];
for(var i=0;i<256;i++) {
  var char=String.fromCharCode(i);
  if(encodeURI(char)!==encodeURIComponent(char)) {
    arr.push({
      character:char,
      encodeURI:encodeURI(char),
      encodeURIComponent:encodeURIComponent(char)
    });
  }
}
console.table(arr);

---

I found this article enlightening : Javascript Madness: Query String Parsing

I found it when I was trying to undersand why decodeURIComponent was not decoding '+' correctly. Here is an extract:

String:                         "A + B"
Expected Query String Encoding: "A+%2B+B"
escape("A + B") =               "A%20+%20B"     Wrong!
encodeURI("A + B") =            "A%20+%20B"     Wrong!
encodeURIComponent("A + B") =   "A%20%2B%20B"   Acceptable, but strange

Encoded String:                 "A+%2B+B"
Expected Decoding:              "A + B"
unescape("A+%2B+B") =           "A+++B"       Wrong!
decodeURI("A+%2B+B") =          "A+++B"       Wrong!
decodeURIComponent("A+%2B+B") = "A+++B"       Wrong!

链接地址: http://www.djcxy.com/p/4504.html

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