从多维数组收集数据？

Question

If I had something like this:

var multi_array = [[1,1], [2,2]];

how could i pull data from the second array in the multi-array and maybe log it to the console.

Answer 1

Well, you couldn't since you effectively have a syntax error. You can't use - in a variable name. But looking past that...

var multi_array = [[1,1], [2,2]];
console.log(multi_array[1]); // Outputs:  [2,2]

The first array is at multi_array[0] , and the second at multi_array[1] . Suppose you wanted to get the second element in the second array:

console.log(multi_array[1][1]);

Answer 2

I guess you don't really mean the second array, but the second value of the inner array. Use map to pick only special values from the inner arrays:

var ar = [[1, 2], [3, 4], [5, 6]];

var new_ar = ar.map(function(inner_ar){
   return inner_ar[1];
});

console.log(new_ar); // [2, 4, 6]