In Eclipse Neon after writing a code, when pressing run, output of other code, (previously done) are showing. The output of the code that i have written is not showing. What is the cause off the problem ? Is it related to workspace ?
Just clicking Run runs whatever program you executed last. It does not switch to your new code.
To be sure of executing your new program right click on the class containing your 'main' method and select 'Run As > Java Program' (assuming this is Java as you haven't told us your programming language).