Hashtable.Contains(object)
Description

Determines whether the Hashtable contains a specific key.

This method implements IDictionary.Contains. It behaves exactly like ContainsKey. This method is an O(1) operation.
// Searchs for a value on the hash table

var h : Hashtable; h = new Hashtable(); h.Add(1,"one"); h.Add(2,"two"); h.Add(3,"two"); if(h.Contains(1)) { Debug.Log("Key '1', has been found!"); }
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public Hashtable h;
    void Example() {
        h = new Hashtable();
        h.Add(1, "one");
        h.Add(2, "two");
        h.Add(3, "two");
        if (h.Contains(1))
            Debug.Log("Key '1', has been found!");
        
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public h as Hashtable

	def Example() as void:
		h = Hashtable()
		h.Add(1, 'one')
		h.Add(2, 'two')
		h.Add(3, 'two')
		if h.Contains(1):
			Debug.Log('Key \'1\', has been found!')