Merge pull request #235 from haskellcamargo/master

Array column with similar core implementation

experimental/array/array_column.js

@@ -0,0 +1,30 @@
+function array_column(array, column_key, index_key) {
+  // +   original by: Marcelo Camargo (https://github.com/haskellcamargo/)
+  // %        note 1: Works only with associative objects, returning an empty
+  // %        note 1: object in case of failure.
+  // *     example 1: var drink, color, power;
+  // *     example 1: array_column([{x: 1, y: 2}, {x: 7, y: 1}], 'x')
+  // *     returns 1: [{0: 1, 1: 7}]
+  // *     example 2: array_column([{x: 1, k: 'a'}, {x: 7, k: 'b'}], 'x')
+  // *     returns 2: [{a: 1, b: 7}]
+
+  var result = {},
+      len    = array.length;
+
+  index_key = index_key || null;
+
+  for (var i = 0; i < len; i++) {
+    if (!typeof array[i] === "object") {
+      continue;
+    } else if (index_key === null && arrya[i].hasOwnProperty(column_key)) {
+      result[i] = array[i][column_key];
+    } else if (array[i].hasOwnProperty(index_key)) {
+      if (column_key === null) {
+        result[array[i][index_key]] = array[i];
+      } else if (array[i].hasOwnProperty(column_key)) {
+        result[array[i][index_key]] = array[i][column_key];
+      }
+    }
+  }
+  return result;
+}