filter
数组中删除空对象
array.filter(el=>{
return typeof el != 'object'
|| Array.isArray(el)
|| Object.keys(el).length > 0
})
map
1.纯数字数组和纯字符串数组之间的转换
arr.map(Number)//全部转为数字
arr.map(String)//全部转为字符串
2.从对象数组中取出特定字段并生成新数组
const arr = [
{a:'123', b:'456', c:'789'},
{a:'222', b:'444', c:'777'},
{a:'333', b:'666', c:'999'},
]
const arr0 = arr.map(e => e.b)//['456','444','666']
可能会持续更新……