title: Angular ForEach in Angular4/Typescript?
body: <p>I see many answers about using ngFor when I search for this, but I understand ngFor.  I'm asking about the <code>angular.forEach()</code> constructor used in my Angular 1 controllers.  These are flagged as errors in TS and do not compile.</p>
  
  <p>For example, I have one with a nested loop:</p>
  
  <pre><code> _this.selectChildren = function (data, $event) {
    var parentChecked = data.checked;
    angular.forEach(_this.hierarchicalData, function (value, key) {
      angular.forEach(value.children, function (value, key) {
        value.checked = parentChecked;
      });
    });
  };
  </code></pre>
  
  <p>What does this construct look like in Typescript for Angular 4?</p>