1. 数组.concat(数组) : 两个数组连成一个新数组
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//声明数组
let arr = [10, 20, 30, 40, 50] // new Array(10,20,30,40,50)
//(1) arr.concat(数组) : 把两个数组连接成一个数组,返回值才是拼接成的新数组
//应用场景: 一般用于长列表(下一页),不断往后面拼接数组
/* let newArr = arr.concat([60, 70, 80, 90])
console.log(newArr) */
let newArr = arr.concat([68, 29, 40])
console.log(newArr) //[10, 20, 30, 40, 50,68,29,40]
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2. 数组.reverse() : 翻转数组
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//(2) arr.reverse() : 翻转数组
//应用场景: 价格从低到高 切换成 从高到低, 只需要翻转数组即可
/* arr.reverse()
console.log(arr) */
let arr = [10, 20, 30, 40, 50]
arr.reverse()
console.log(arr) //[50,40,30,20,10]
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3. 数组.join('分隔符')
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//(3) arr.join('分隔符') : 把数组每一个元素拼接成字符串
let arr1 = [80, 90, 55, 60]
//应用场景 : 有些歌曲是多个人合唱,服务器会给我们一个数组,这个时候就需要将数 组元素通过join拼接起来然后再页面显示
/* let str = arr1.join('&')
console.log(str) //80&90&55&60 */
let str = arr1.join('')
console.log(str) //80905560
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4. 数组的排序
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//(4) arr.sort( function(a,b){return a-b} ) : 排序
/* let arr2 = [80, 90, 50, 20, 77, 88]
arr2.sort(function (a, b) {
// return a-b //从小到大
return b - a //从大到小
})
console.log(arr2) */
let numArr = [10, 50, 30, 65, 80]
numArr.sort(function (a, b) {
// return a-b//从小到大
return b - a //从大到小
})
console.log(numArr)//[80, 65, 50, 30, 10]
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