Page 335 - Web Applications (803) Class 11
P. 335

</HEAD>
                   <BODY>
                   <H3> Using Nested Loop</H3>
                   <SCRIPT>
                   var i, j;
                   for(i=1; i <= 5; i++)
                   {
                   for(j=1; j<=i; j++)
                   {
                   document.write(“*”);
                   }
                   document.write(“<br />”);
                   }
                   </SCRIPT>
                   </BODY>
                   </HTML>
                 Output:















                 Infinite Loop

                 An infinite loop is a piece of code that never ends because it never reaches the ending condition. An infinite loop might
                 cause your software or browser to fail and your machine to become unresponsive. In order to avoid such situations,
                 we must be aware of infinite loops and how to avoid them.
                 Let’s look at some examples of how infinite loops can occur. When the while statement’s condition is set to true, one
                 of the most typical infinite loops occurs as shown:
                 var i=5;
                 while (true) {
                     document.write(i); // execute code forever
                 }
                 By omitting all parts of the head of a for() block, you can easily wind up in an infinite loop :

                   for ( ; ;) {
                     //statements are will execute forever
                   }
                 How do you avoid becoming stuck in an infinite loop?

                 Ð ÐWithin the for() loop: Ensure that the statements in the for() block never affect the value of the loop counter
                   variable to avoid ending up in an infinite loop. If they do, your loop can terminate prematurely or loop indefinitely.

                 Ð ÐLoops  in  while  and  do-while:  Ensure  that  the  loop  has  at  least  one  statement  that  changes  the  value  of  the
                   comparison variable. (That is, the variable used in the comparison statement of the loop.) Otherwise, the condition
                   may always return true, resulting in an endless cycle.

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