js实现url链接encode加密

function urlencode(clearString) {
var output = '';
var x = 0;

clearString = utf16to8(clearString.toString());
var regex = /(^[a-zA-Z0-9-_.]*)/;

while (x < clearString.length) {
var match = regex.exec(clearString.substr(x));
if (match != null && match.length > 1 && match[1] != '') {
output += match[1];
x += match[1].length;
} else {
if (clearString[x] == ' ') {
output += '+';
} else {
var charCode = clearString.charCodeAt(x);
var hexVal = charCode.toString(16);
output += '%' + ( hexVal.length < 2 ? '0' : '' ) + hexVal.toUpperCase();
}
x++;
}
}
return output;
}

function utf16to8(str) {
var out, i, len, c;
out = "";
len = str.length;
for(i = 0; i < len; i++) {
c = str.charCodeAt(i);
if ((c >= 0x0001) && (c <= 0x007F)) {
out += str.charAt(i);
} else if (c > 0x07FF) {
out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
} else {
out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
}
}
return out;
}