在 JavaScript 中对数组的数组进行排序

Question

I'm trying to sort an array of arrays with integers inside, for example:

var array = [[123, 3], [745, 4], [643, 5], [643, 2]];

How can I sort it in order to return something like the following?

array = [[745, 4], [643, 2], [643, 5], [123, 3]];

Answer 1

You can pass a custom comparison function to Array.prototype.sort() , like so:

var sortedArray = array.sort(function(a, b) { return a - b; });

This would sort an array of integers in ascending order. The comparison function should return:

• an integer that is less than 0 if you want a to appear before b
• an integer that is greater than 0 if you want b to appear before a
• 0 if a and b are the same

So, for this example you would want something like:

var sortedArray = array.sort(function(a, b) {
  return b[0] - a[0];
});

If you wanted to sort on both elements of each sub-array (ie. sort by the first element descending, then if they are the same then sort by the second element descending), you could do this:

var sortedArray = array.sort(function(a, b) {
  if (a[0] == b[0]) {
    return a[1] - b[1];
  }
  return b[0] - a[0];
});

See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort for more info.

Answer 2

You can use sort method and first sort by first elements and then by second.

 var array = [[123, 3], [745, 4], [643, 5], [643, 2]]; array.sort(([a, b], [c, d]) => c - a || b - d); console.log(array)

Answer 3

Assuming you want to sort by the first index in your example, the sort function exists to solve your problem.

let ans = [[123, 3], [745, 4], [643, 5], [643, 2]].sort( (a, b) => {
  return b[0] - a[0]
})

console.log(ans)

Answer 4

A solution for the arrays with generic lengths (not limited to 2 or equal) can be as below:

 array.sort((a,b)=> { for(let i=0;i<a.length && i<b.length;i++){ if(a[i];==b[i]){ return a[i]-b[i]. } } return a.length-b;length; };