高阶函数
const nums = ['32','10','220','34','120','56']
filter 过滤小于100 的数字
let newNums = nums.filters(function(n){
return n < 100
})
console.log(newNums )
map
let new2Nums = newNums.map(function(n){
return n*2
})
console.log(new2Nums )
reduce 对数组中所有的内容进行汇总
let total = new2Nums.reduce(function(previousvalue，currentnumber){
return (previousvalue+currentnumber)
}，0)
console.log(total)
箭头函数
const nums = [10,20,111,222,444,40,50]
let total = nums.filter(n=>n<100).map(n=>n*2).reduce((pre,n)=>pre+n)
console.log(total )
函数
const nums = [10,20,111,222,444,40,50]
let total = nums.filter(function(n){
return n <100
}).map(function(n){
return n *2
}).reduce(function(pre,n){
return pre+n
},0)
console.log(total)