Source code in the netrexx programming language

/*NetRexx program to display the 1st 8 (or specified arg) happy numbers*/
limit	 = arg[0]                        /*get argument for  LIMIT.        */
say limit
if limit = null, limit ='' then limit=8  /*if not specified, set LIMIT to 8*/
haps	 = 0                             /*count of happy numbers so far.  */

loop n=1 while haps < limit              /*search integers starting at one.*/
  q=n                                    /*Q may or may not be "happy".    */
  a=0
  
  loop forever                           /*see if  Q  is a happy number.   */
    if q==1 then do                      /*if  Q  is unity, then it's happy*/
      haps = haps + 1                    /*bump the count of happy numbers.*/
      say n                              /*display the number.             */
      iterate n                          /*and then keep looking for more. */
    end
    
    sum=0                                /*initialize sum to zero.         */
    
    loop j=1 for q.length                /*add the squares of the numerals.*/
      sum = sum + q.substr(j,1) ** 2
    end
    
    if a[sum] then iterate n             /*if already summed, Q is unhappy.*/
    a[sum]=1                             /*mark the sum as being found.    */
    q=sum                                /*now, lets try the  Q  sum.      */
  end
end