函数式编程

(function () {

    var add = function (x) {
        return function (y) {
            return x + y;
        }
    };

    var a = add(1);
    console.log(a(2)); //3

})();

var addOne=add(1);
addOne(1); //1+1
addOne(2); //1+2
addOne(3); //1+3

(function () {

    var compose=function (f,g) {
        return function (x) {
            return f(g(x));
        }
    };

    var getHead=function (x) {return x[0]};
    var toUpperCase=function (x) {return x.toUpperCase();};

    var controlString=compose(getHead,toUpperCase);

    var str=‘meng‘;
    console.log(controlString(str));
})();