Javascript可变长度参数列表 － Arguments对象

function f(x, y, z) {
  if (arguments.length != 3) {
    throw new Error("function with " + arguments.length +
        "arguments, but it expects 3 arguments.")
    
    // now do the actual function
  }        
}

function max() {
    var m = Number.NEGATIVE_INFINITY;
    for (var i = 0; i  < arguments.length; i++) {
        if (arguments[i] > m) m = arguments[i];
    }
    
    return m;
}

function f(x) {
    if (x <= 1) return 1;
    
    return x * arguments.callee(x - 1);
}