标签：sel undefined 去重 lte 图片 new elf def title
1.创建一个数组，判断数组中是否存在某个值
var newarr = [
{ num: 1, val: ‘ceshi‘, flag: ‘aa‘ },
{ num: 2, val: ‘ceshi2‘, flag: ‘aa2‘ }
]
console.log(newarr.filter(item => item.num===2 ))
2.也可以通过上面方法过滤掉num为2的留下num为1的
var newarr = [
{ num: 1, val: ‘ceshi‘, flag: ‘aa‘ },
{ num: 2, val: ‘ceshi2‘, flag: ‘aa2‘ }
]
console.log(newarr.filter(item => item.num!=2 ))
3.去掉空数组空字符串、undefined、null
var arr = [‘1‘,‘2‘,undefined, ‘3.jpg‘,undefined] var newArr = arr.filter(item => item) console.log(newArr) var arr = [‘1‘,‘2‘,null, ‘3.jpg‘,null] var newArr = arr.filter(item => item) console.log(newArr) >//空字符串里面不能包含空格 var arr = [‘1‘,‘2‘,‘‘, ‘3.jpg‘,‘‘] var newArr = arr.filter(item => item) console.log(newArr)
4.去掉数组中不符合项
var arr = [20,30,50, 96,50] var newArr = arr.filter(item => item>40) console.log(newArr)
5.过滤不符合项
var arr = [‘10‘,‘12‘,‘23‘,‘44‘,‘42‘] var newArr = arr.filter(item => item.indexOf(‘2‘)<0) console.log(newArr)
6.数组去重
var arr = [1, 2, 2, 3, 4, 5, 5, 6, 7, 7,8,8,0,8,6,3,4,56,2]; var arr2 = arr.filter((x, index,self)=>self.indexOf(x)===index) console.log(arr2); //[1, 2, 3, 4, 5, 6, 7, 8, 0, 56]
标签：sel undefined 去重 lte 图片 new elf def title
原文地址：https://www.cnblogs.com/sexintercourse/p/11802498.html
