Eclipse modifies the number of characters per line (Java class)

The procedure is as follows:
Choose window> preferences> java> code style> formatter.
OK. The next operation is the interface operation.
There is a drop-down menu with three options:

1. java conventions
2. eclipse
3. eclipse2.1
This template provided by eclipse cannot be modified.
We want to create a new
Click the new button under the menu.
Enter yourEclipse in profile name
Select eclipse [built-in] from the drop-down menu.
Click OK
Profile created
Next, set this prifile.
Select yourEclipse --> edit button ---> line wrapping ---> max line width
120
Try ctrl + shift + F to see the effect