Make a program that filters a list of strings and returns a list with only your friends name in it.
If a name has exactly 4 letters in it, you can be sure that it has to be a friend of yours!
Ex: Input = ["Ryan", "Kieran", "Jason", "Yous"], Output = ["Ryan", "Yous"]
简单来说就是找出数组中所有四个字符的字符串
function friend(friends){
//your code here
var arr=friends.filter(function(x,index){
return x.length==4;
})
return arr;
}
测试数据：
friend(["Ryan", "Kieran", "Mark"]), ["Ryan", "Mark"];
friend(["Ryan", "Jimmy", "123", "4", "Cool Man"]), ["Ryan"];
friend(["Jimm", "Cari", "aret", "truehdnviegkwgvke", "sixtyiscooooool"]), ["Jimm", "Cari", "aret"];
friend(["Love", "Your", "Face", "1"]), ["Love", "Your", "Face"];
最佳答案
function friend(friends){ return friends.filter(n => n.length === 4) }
原文：http://www.cnblogs.com/chengnanbei/p/7233223.html