map 方法：可以簡單的理解為對映

var num = [1,2,3,4];
var dataAdd = num.map(n => n+n);
var datadeep = num.map(n => n-1);
console.log(dataAdd);//[2, 4, 6, 8]
console.log(datadeep);//[0,1,2,3]

filter方法: 過濾篩選的作用，陣列filter後，返回的結果為新的陣列

		var chinaWords = [{
			name:"君住長江頭",
			msg:"詩詞",
			age:15
		},{
			name:"我住長江尾",
			msg:"歌賦",
			age:15
		},{
			name:"日日思君不見君,同飲一江水",
			msg:"古風",
			age:14
		}]
		
		var dataname = chinaWords.map(one => one.name)
		console.log(dataname.join(','));//君住長江頭,我住長江尾,日日思君不見君,同飲一江水
		
		var oneages = chinaWords.map(one => one.age)
		console.log(oneages.join(','));//15,15,14
		var ageJudge = oneages.filter(age => age > 14 )
		console.log(ageJudge.join(','));//15,15