map()函数

map()：是指原数组中每个元素调用一个指定方法后的返回值组成的新数组，看官网上的代码解释

function fuzz(single){
    var result=single.replace(/o/g,'e');
   if(single=='kangaroo'){
        result+='se';
    }          
   return result;
}
var words=['foot','goose','moose',''kangaroo'];
console.log(words.map(fuzz));//['feet','geet','meese','kangareese'];

single.replace(/o/g,'e')的意思是全局的'o'都变成'e'