数组排序

var arr = [1, 5, 2, 9, 10, 8];
var min;
for (var i=0; i<arr.length-1; i++)  {
    for (var j=i+1; j<arr.length; j++)  {
         if (arr[i]>arr[j]) {
            ts = arr[j];
            arr[j] = arr[i];
            arr[i] = ts;               
         }
    }
} 
console.log(arr); // [1, 2, 5, 8, 9, 10]

var arr = [1, 5, 2, 9, 10, 8];
arr.sort(function(a, b) {
    if (a>b) {
        return 1;
    } else if (a<b) {
        return -1;
    } else {
        return 0;
    }
});
// [1, 2, 5, 8, 9, 10]

var arr = [1, 5, 2, 9, 10, 8];
var max;
for (var i=0; i<arr.length-1; i++)  {
    for (var j=i+1; j<arr.length; j++)  {
         if (arr[i]<arr[j]) {
            ts = arr[j];
            arr[j] = arr[i];
            arr[i] = ts;               
         }
    }
} 
console.log(arr); // [10, 9, 8, 5, 2, 1]

var arr = [1, 5, 2, 9, 10, 8];
arr.sort(function(a, b) {
    if (a>b) {
        return -1;
    } else if (a<b) {
        return 1;
    } else {
        return 0;
    }
});
// [10, 9, 8, 5, 2, 1]