Q:

Angular ForEach in Angular4/Typescript?

I see many answers about using ngFor when I search for this, but I understand ngFor.  I'm asking about the angular.forEach() constructor used in my Angular 1 controllers.  These are flagged as errors in TS and do not compile.
For example, I have one with a nested loop:
 _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;
    });
  });
};

What does this construct look like in Typescript for Angular 4?

A:

in angular4 foreach like that. try this.   
 selectChildren(data, $event) {
      let parentChecked = data.checked;
       this.hierarchicalData.forEach(obj => {
          obj.forEach(childObj=> {
            value.checked = parentChecked;
         });
      });
    }

A:

you can try typescript's For  : 
selectChildren(data , $event){
   let parentChecked : boolean = data.checked;
   for(let o of this.hierarchicalData){
      for(let child of o){
         child.checked = parentChecked;
      }
   }
}

