March 2018
Beginner
378 pages
8h 45m
English
Content preview from Learning Swift, 3rd Edition
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Chapter 17. Debugging
Selfiegram is complete, and we’re at the point where we want to start shipping it off for people to start testing—right? But what if there are bugs in the code? How would we go about finding and squashing them? What about the performance of Selfiegram? Is the app snappy and responsive? Are we leaking memory or taking too long to load resources? In this chapter we are going to be looking at how we can use the debugger in Xcode to find bugs, and the Instruments app to monitor and performance-test our app.
The Debugger
No one is perfect, especially not when it comes to writing code. There are so many tiny pieces all in play that small mistakes can easily get lost in the codebase. Eventually these little bugs will cause issues, and you’ll have to fix them—but they can be buried many layers deep in your code, so how do you find them?
This is where the debugger comes in. The debugger lets you move through your code line by line, action by action, inspecting and querying the running program as you go.
Note
Depending on your previous experience with debuggers, this section might be a bit dull. The Xcode debugger (LLDB) is very similar in design and function to all other debuggers.
The basic operation of the debugger is the same regardless of what you are debugging. You run your app through the debugger, and it will run the program like normal but will halt execution at certain points to let you inspect the code and give you control over how to continue execution. ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.