Javascript: Multidimensional array sort by specified index?

With a simple sort callback

var arr = [[1,5,2],[1,8,2],[1,2,2]];

console.log( arr );

arr.sort( function( a, b )
{
  // Sort by the 2nd value in each array
  if ( a[1] == b[1] ) return 0;
  return a[1] < b[1] ? -1 : 1;
});

console.log( arr );

the Array.sort() method takes a callback into which two elements are passed. It's a basic bubble sort

• If a is to be sorted ahead of b, return -1 (or any negative value)
• If b is to be sorted ahead of a, return 1 (or any positive value)
• If a and b are equal, return 0;