The keys() function of Map object is similar to entries but, it returns an iterator object containing the keys of a map object.
Syntax
Its Syntax is as follows
Map.keys()
Example
<html> <head> <title>JavaScript Example</title> </head> <body> <script type="text/javascript"> var mapVar = new Map(); mapVar.set('1', 'Java'); mapVar.set('2', 'JavaFX'); mapVar.set('3', 'HBase'); mapVar.set('4', 'Neo4j'); var it = mapVar.keys(); for(i=0; i<mapVar.size; i++) { document.write(it.next().value); document.write(" <p> "); } </script> </body> </html>
Output
1 2 3 4