下面的javascript函数可以对php urlencode函数生成的编码做解码操作：

function urldecode(encodedString){

var output = encodedString;

var binVal, thisString;

var myregexp = /(%[^%]{2})/;

function utf8to16(str)

{

var out, i, len, c;

var char2, char3;

out = "";

len = str.length;

i = 0;

while(i < len)

{

c = str.charCodeAt(i++);

switch(c >> 4)

{

case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:

out += str.charAt(i-1);

break;

case 12: case 13:

char2 = str.charCodeAt(i++);

out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));

break;

case 14:

char2 = str.charCodeAt(i++);

char3 = str.charCodeAt(i++);

out += String.fromCharCode(((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0));

break;

}

}

return out;

}

while((match = myregexp.exec(output)) != null

&& match.length > 1

&& match[1] != '')

{

binVal = parseInt(match[1].substr(1),16);

thisString = String.fromCharCode(binVal);

output = output.replace(match[1], thisString);

}

output = output.replace(/\\+/g, " ");

output = utf8to16(output);

return output;

}