Add walkThrough

snippets/walkThrough.md

@@ -0,0 +1,62 @@
+---
+title: walkThrough
+tags: object,recursion,generator,advanced
+---
+
+Creates a generator, that walks through all the keys of a given object.
+
+- Use recursion.
+- Define a generator function, `walk`, that takes an object and an array of keys.
+- Use a `for...of` loop and `Object.keys()` to iterate over the keys of the object.
+- Use `typeof` to check if each value in the given object is itself an object.
+- If so, use the `yield*` expression to recursively delegate to the same generator function, `walk`, appending the current `key` to the array of keys. Otherwise, `yield` the an array of keys representing the current path and the value of the given `key`.
+- Use the `yield*` expression to delegate to the `walk` generator function.
+
+```js
+const walkThrough = function* (obj) {
+  const walk = function* (x, previous = []) {
+    for (let key of Object.keys(x)) {
+      if (typeof x[key] === 'object') yield* walk(x[key], [...previous, key]);
+      else yield [[...previous, key], x[key]];
+    }
+  };
+  yield* walk(obj);
+};
+```
+
+```js
+const obj = {
+  a: 10,
+  b: 20,
+  c: {
+    d: 10,
+    e: 20,
+    f: [30, 40]
+  },
+  g: [
+    {
+      h: 10,
+      i: 20
+    },
+    {
+      j: 30
+    },
+    40
+  ]
+};
+[...walkThrough(obj)];
+/*
+[
+  [['a'], 10],
+  [['b'], 20],
+  [['c', 'd'], 10],
+  [['c', 'e'], 20],
+  [['c', 'f', '0'], 30],
+  [['c', 'f', '1'], 40],
+  [['g', '0', 'h'], 10],
+  [['g', '0', 'i'], 20],
+  [['g', '1', 'j'], 30],
+  [['g', '2'], 40]
+]
+*/
+```