JavaScript topic, rewrite function let it infinite add _javascript technique

function Add (x) {________}; Alert (Add (2) (3) (4)); Fill in the blanks so that the result is 9
Solution One,

Copy Code code as follows:

Tapir Big
function Add (x) {
var c = 0;
return function (x) {
c = c + x; arguments.callee.toString = function () {
return C;
};
return Arguments.callee;
} (x);
};
Alert (Add (2) (3) (4));

Solution Two,

Copy Code code as follows:

San GUI
function Add (x) {
return function (y) {
return function (z) {
return x+y+z;
}
}
};
Alert (Add (2) (3) (4));

Solution Three,

Copy Code code as follows:

Masaki
function Add (a) {
if (!isfinite (ADD.I)) {
ADD.I = A
}else {
ADD.I + A;
}
add.valueof = add.tostring = function () {
Return ADD.I
}
return add;
}
Alert (Add (2) (3) (4))

In fact, the last question is the test curry, see me another blog.
If you have a different solution, please also give a lot of advice!