Modify a value during iOS debugging in Xcode

Modify a value during iOS debugging in Xcode


1 min read

Xcode is using the open-source LLDB debugger and with the expression command you are able to modify a value in a running program.

Use expression in debugger

You can verify that the value has changed with the print command from LLDB.

Screen Shot 2022-07-11 at 1.15.53 PM.png

Once you resume the program you will see that the changed value is still used.

Bonus tip 1: You can also use the abbreviation e as alternative to the verbose expression because LLDB does prefix matching. Same for p as alternative to print.

Bonus tip 2: You can use multiple expressions as actions in the Xcode debugger ti supply test/demo data. Find out more by reading Dominik Hauser's article.

Using breakpoints to populate with demo data