[SOLVED] Problem with "foreach".

I'm making script that'll select nearest object with tag. It's this:

 using UnityEngine;
 using System.Collections;
 using System;
 
 public class IfCloseEnought : MonoBehaviour {
 
     public GameObject[] enemies;
     public float range = 10;
     public float minimalDistance = 65879;
     public float measureDistance;
     public GameObject target;
     private int number;
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
         enemies = GameObject.FindGameObjectsWithTag ("Enemy");
         foreach (GameObject enemy in enemies) {
             measureDistance = Vector3.Distance(gameObject.transform.position, enemy.transform.position);
             if(measureDistance < minimalDistance && measureDistance < range){
                 target = enemy;
                 minimalDistance = measureDistance;
                 number++;
             }
         if(target == null){
                 minimalDistance = 65879;
         }
         if(target != null){
             if(Vector3.Distance(gameObject.transform.position, target.transform.position) > range){
                     target = null;
             }
         }
             Array.Clear(enemies, 0, enemies.Length);
             number = 0;
             Debug.Log(target);
             Debug.Log(minimalDistance);
         }
 
 
     }
 }
 

The problem is somewhere in foreach loop (i think). It's executed only on 0th element of array, and doesn't calculate distance between gameObject and elements 1, 2, 3...

It also outputs this error:

NullReferenceException: Object reference not set to an instance of an object IfCloseEnought.Update () (at Assets/Scripts/IfCloseEnought.cs:22)

Where's problem and how to fix it?