The purpose of a while loop is to execute a statement or code block repeatedly as long as an expression is true. Once the expression becomes false, the loop terminates.
You can try to run the following code to learn how to use nested while loop
<html> <body> <script> var height = 2; var width = 8; var col = 0; var row = 0; document.write("Starting Loop<br> "); while (row < height) { col = 0; while(col < width) { document.write("#"); col++; } document.write("<br>"); row++; } document.write("Loop stopped!"); </script> </body> </html>