[рони]

Роман1479,

var matrix4D = [
  [1, 1, 1, 1],
  [1, 1, 1, 1],
  [1, 1, 1, 1],
  [1, 1, 1, 1]
];
var matrix4_D = [
  [1, 1, 1, 3],
  [1, 1, 6, 1],
  [1, 2, 1, 10],
  [9, 1, 1, 1],
  [1, 1, 11, 1]
];


var matrix5D = [
  [1, 2, 3, 4, 5],
  [1, 1, 1, 3, 4],
  [1, 1, 1, 1, 1]
];

function function_matrix(arr){
    var num = arr[0].length;
    var l = Math.min(num, arr.length)
    var n = --num;
    var res = [];

    for (var i = 0; i < l; i++) {
        res.push(arr[i][n])
        --n
    }
    return res
}
alert(function_matrix(matrix4D));
alert(function_matrix(matrix4_D));
alert(function_matrix(matrix5D));