Javascript遍历包含逗号分隔值的数组键

Question

I am trying to figure out the best way to split a object that has many key value pairs over 800 points ( they are X and Y coordinates)

I would like to split X into its own array and Y into a separate array so that I can access X alone and Y alone.

Here is the structure of the points and what I have attempted

var path = {
    0: [41, -73],
    1: [41, -74],
    2: [42, -75],
    3: [43, -76]
};

for (var key in path) {
    console.log("key " + key + " has value " + path[key]);
}

This will log

  key 0 has value 41,-73 

  key 1 has value 42,-74 

  key 2 has value 43,-75 

  key 3 has value 44,-76

I need the first value to be stored in its own array and the second value into another array.

For example I would like to access all of X and Y as such,

var x = [41, 42, 43, 44]
var y = [-73,-74,-75,-76]

JS FIDDLE HERE http://jsfiddle.net/b3j4w9bv/14/

Thanks!

Answer 1

You could do something along these lines:

var path = {
0: [41, -73],
1: [41, -74],
2: [42, -75],
3: [43, -76]
};

var x_path = [];
var y_path = [];

for(var key in path)
{
   //console.log("key " + key + " has value " + path[key]);
   //create a split on , for x & y
   var split_path = path[key];
   //grab the value of the split:
   var x = split_path[0];
   var y = split_path[1];

    //add the coords to their arrays.
    x_path.push(x);
    y_path.push(y);

    //output result:
    console.log(x_path);
    console.log(y_path);
}

I haven't tested this in terms of perfomance..it might not be the most efficient

fiddle: http://jsfiddle.net/g123vyuv/