title: Get all children from parent child JSON data
body: <p>I have parent-child JSON data and I want get all children (nested children) from selected parent.</p>
  
  <p>For example, I have JSON data :</p>
  
  <pre><code>[{
    "id": 1,
    "parent": 0,
    "name": "Parent"
  }, {
    "id": 2,
    "parent": 1,
    "name": "Child 1"
  }, {
    "id": 3,
    "parent": 2,
    "name": "Grand Child 1"
  }, {
    "id": 4,
    "parent": 2,
    "name": "Grand Child 2"
  }, {
    "id": 5,
    "parent": 1,
    "name": "Child 2"
  }]
  </code></pre>
  
  <p>And I have function findAllChildren(1), where "1" is "parent" and then result of function should be :</p>
  
  <pre><code>[{
    "id": 2,
    "parent": 1,
    "name": "Child 1"
  }, {
    "id": 3,
    "parent": 2,
    "name": "Grand Child 1"
  }, {
    "id": 4,
    "parent": 2,
    "name": "Grand Child 2"
  }, {
    "id": 5,
    "parent": 1,
    "name": "Child 2"
  }]
  </code></pre>
  
  <p>And in other case, if i call findAllChildren(2), result of the function should like below :</p>
  
  <pre><code>[{
    "id": 3,
    "parent": 2,
    "name": "Grand Child 1"
  }, {
    "id": 4,
    "parent": 2,
    "name": "Grand Child 2"
  }]
  </code></pre>
  
  <p>What is the proper way to create function to solve that case? Thank you.</p>