// Questions array:
const questions = [
    {
      "form_criteria_id":"46",
      "field_name":"pumpstation_general",
      "field_label":"General repairs required?",
      "mandatory":false,
      "action":"dropdown",
      "input_type":[
         {
            "id":7,
            "text":"Yes",
            "value":"yes",
            "created_at":"2018-10-21 22:36:18",
            "updated_at":"2018-10-21 22:36:18"
         },
         {
            "id":8,
            "text":"No",
            "value":"no",
            "created_at":"2018-10-21 22:36:18",
            "updated_at":"2018-10-21 22:36:18"
         }
      ],
      "value":""
   },
   {
      "form_criteria_id":"60",
      "field_name":"pumpstation_control_panel_photo",
      "field_label":"Control panel photos",
      "mandatory":false,
      "action":"upload",
      "input_type":[

      ],
      "value":""
   }
]

// Answers array:
const answers = [
   {
      "id":"1",
      "form_id":1,
      "form_criteria_id":46,
      "form_criteria_option_id":7,
      "value":"yes",
      "text":"Yes"
   }
]

// Merge into
[
    {
      "form_criteria_id":"46",
      "field_name":"pumpstation_general",
      "field_label":"General repairs required?",
      "mandatory":false,
      "action":"dropdown",
      "input_type":[
         {
            "id":7,
            "text":"Yes",
            "value":"yes",
            "created_at":"2018-10-21 22:36:18",
            "updated_at":"2018-10-21 22:36:18"
         },
         {
            "id":8,
            "text":"No",
            "value":"no",
            "created_at":"2018-10-21 22:36:18",
            "updated_at":"2018-10-21 22:36:18"
         }
      ],
      "value":"yes" /** Set the answer here for criteria id of 46 **/
   },
   {
      "form_criteria_id":"60",
      "field_name":"pumpstation_control_panel_photo",
      "field_label":"Control panel photos",
      "mandatory":false,
      "action":"upload",
      "input_type":[

      ],
      "value":""
   }
]

// Solution?
questions.forEach(q => {
    answers.forEach(a => {
        if (a.form_criteria_id == q.form_criteria_id) {
            return q.value = a.value;
        }
    });
});

// Alternate??
questions.map(q => {
    answers.filter(a => {
        return q.form_criteria_id == a.form_criteria_id ? q.value = a.value : '';
    });
});
console.log(questions);