函数作为参数传递

function map(f, a) {
  var result = []; // 创建一个数组
  var i; // 声明一个值，用来循环
  for (i = 0; i != a.length; i++)
    result[i] = f(a[i]);
      return result;
}
var f = function(x) {
   return x * x * x; 
}
var numbers = [0,1, 2, 5,10];
var cube = map(f,numbers);
console.log(cube);

https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Guide/Functions