1、concat:用于拼接为新数组
let arr = [1, 2, 3]
let arr1 = ['a', 'b', 'c']
let arr2 = [11, 22, 33, 44]
let reArr = arr.concat(arr1, arr2, 'o', '上海')
console.log(reArr)
2、join() 用于连接数组的每个元素成为字符串
let arr = ['a', 'b', 'c']
let str = arr.join('')
console.log(str)
3、reverse:翻转数组顺序
4、sort 排序
let arr = [3, 16, 22, 66, 123, 99]
//正序排列 逆序b-a
let re = arr.sort((a, b) => {
return a - b
})
console.log(re)
5、isArray判断一个值是不是数组
let a = [1, 2, 3]
let re = Array.isArray(a)
console.log(re)
6、Array.from() 把伪数组转换为真数组 必须有length属性
let o = {
0: 'a',
1: 'b',
length: 2
}
let arr = Array.from(o)
console.log(arr)
ul>li*10{$}---------10个小粒 获取全部的小粒 得到的是一个伪数组
要想删掉最后一个
得先把为数组转为真数组 在pop
7、forEach 遍历数组(重点)
let arr = ['a', 'b', 'c']
arr.forEach(function(item, index, arr) {
//item:代表数组的每一项
//index:下标
//arr:数组本身
console.log(item, index, arr)
})
let arr = [{
name: 'zs1',
age: 18
}, {
name: 'zs2',
age: 18
}, {
name: 'zs3',
age: 18
}, {
name: 'zs4',
age: 18
}]
arr.forEach(item => {
console.log(`姓名:${item.name},年龄${item.age}`)
})