Update rand.rst

docs/rand.rst

@@ -58,5 +58,27 @@ Example 1
     }
   }
 
-**Note** You should NOT call `rand()` in a `view` or `pure` function. If the random number does not need to be recorded on the blockchain (i.e., outside of a transaction in a `view` function executed on a single node), it does not need to be generated by the blockchain. The calling application should simply generate a random number locally -- it is much cheaper in terms of resource consumption.
+.. WARNING::
+  You should NOT call `rand()` in a `view` or `pure` function. If the random number does not need to be recorded on the blockchain (i.e., outside of a transaction in a `view` function executed on a single node), it does not need to be generated by the blockchain. The calling application should simply generate a random number locally -- it is much cheaper in terms of resource consumption.
+
+The example below shows how to generate a series of random numbers between 0 and 99. You can invoke `createRand()` multiple times within a block (i.e., wthin 10s) or across multiple blocks to see the results.
+
+.. code-block:: Lity
+
+  pragma lity >=1.2.6;
+
+  contract RandDemo {
+    uint[] s;
+  
+    function createRand () public {
+      s.push(rand() % 100);
+    }
+  
+    function last5Rands () public view returns (uint, uint, uint, uint, uint) {
+      require (s.length >= 5);
+      return (s[s.length-1], s[s.length-2], s[s.length-3], s[s.length-4], s[s.length-5]);
+    }
+  }
+
+