柯里化函数

function curry(fn){
 var args = Array.prototype.slice.call(arguments, 1);
 return function(){
 var innerArgs = Array.prototype.slice.call(arguments);
 var finalArgs = args.concat(innerArgs);
 return fn.apply(null, finalArgs);
 };
} 

 Demo

function add(num1, num2){
 return num1 + num2;
}
var curriedAdd = curry(add, 5);
alert(curriedAdd(3)); //8 

 

function add(num1, num2){
 return num1 + num2;
}
var curriedAdd = curry(add, 5, 12);
alert(curriedAdd()); //17 

 函数柯里化还常常作为函数绑定的一部分包含在其中，构造出更为复杂的 bind()函数。例如：

 

function bind(fn, context){
 var args = Array.prototype.slice.call(arguments, 2);
 return function(){
 var innerArgs = Array.prototype.slice.call(arguments);
 var finalArgs = args.concat(innerArgs);
 return fn.apply(context, finalArgs);
 };
} 

 

var handler = {
 message: "Event handled",
 handleClick: function(name, event){
 alert(this.message + ":"+ name + ":"+ event.type);
 }
};
var btn = document.getElementById("my-btn");
EventUtil.addHandler(btn, "click", bind(handler.handleClick, handler, "my-btn"));