突然需要对数组进行排序，然后才又回过头来温习这东西，真的超久没用到了…(⊙＿⊙；)…
按照习惯通过看例子进行了解吧。
例1：
var arr = []
arr[0] = "xiaodong"
arr[1] = "zhangyu"
arr[2] = "huyong"
arr[3] = "minglin"
arr[4] = "dasheng"
arr[5] = "anan"
console.log(arr.sort()) //排序后：["anan", "dasheng", "huyong", "minglin", "xiaodong", "zhangyu"]
例2：
var arr = []
arr[0] = "10"
arr[1] = "5"
arr[2] = "40"
arr[3] = "25"
arr[4] = "1000"
arr[5] = "1"
console.log(arr) //排序前：["10", "5", "40", "25", "1000", "1"]
console.log(arr.sort()) //排序后：["1", "10", "1000", "25", "40", "5"]，明显可以看出这里并没有按照数字大小排列，而是以字符串的形式按照首字母依次排序的
例3：
function sortIncrease(a,b){
return a - b
}
function sortDecrease (a,b){
return b - a
}
var arr = []
arr[0] = "10"
arr[1] = "5"
arr[2] = "40"
arr[3] = "25"
arr[4] = "1000"
arr[5] = "1"
console.log(arr.sort(sortIncrease)) //递增排序后：["1", "5", "10", "25", "40", "1000"]
console.log(arr.sort(sortDecrease)) //递减排序后：["1000", "40", "25", "10", "5", "1"]
完。
