Why I can't change directories using “cd”?

Question

I\'m trying to write a small script to change the current directory to my project directory:

#!/bin/bash
cd /home/tree/projects/java

I save

Answer 1

When you fire a shell script, it runs a new instance of that shell (/bin/bash). Thus, your script just fires up a shell, changes the directory and exits. Put another way, cd (and other such commands) within a shell script do not affect nor have access to the shell from which they were launched.