CODEWITHSUNDEEP
iphonexcodegdbdebugging
4thSpace
4thSpace

Reputation: 44310

How to print string value from breakpoint action in Xcode 4?

I have a breakpoint action and am using the Log option from the drop down. I'd like to print out the string (summary) value. I'm doing this:

the person name is: @p.name@

but that prints the memory address. I can switch to the Debugger Command option and do

po f.name

but then I lose my description, as used in the first option. Using the Log option, is there a way to print the string value and not the memory address?

Upvotes: 25

Views: 18072

Answers (6)

rgkobashi
rgkobashi

Reputation: 2698

For Swift and Xcode 12.2 you can double click on the breakpoint and use Debugger Command as an action and as a command whatever you usually time on the debugger.

In the example I use po with a string as param (to avoid printing the memory address) which contains the values I am debugging. I also enable Automatically continue... to avoid stopping the execution.

enter image description here

You can also add other text or other variables.

A thing to keep in mind though, running these takes some time, so for operations where timing is important, these are not good.

Upvotes: 1

LukeSideWalker
LukeSideWalker

Reputation: 7900

You don't need TWO actions in the breakpoint, you can just have ONE command (log message), where you put the message including the content of variables (see image). By clicking "automatically continues" it is just acting like having a print-command in code, but the good thing is, then you dont have print statements in your code.

enter image description here

Upvotes: 0

Skotch
Skotch

Reputation: 3091

Here is a solution using only one action, and using fewer characters than the expr solution.

debugger command using NSlog

However, unless you add the void like this:

po (void)NSLog(@"the person name is: %@", p.name)

you will get an annoying "nil" printed out with your log. for example:

(lldb) po NSLog(@"foo")
 nil
2013-06-19 14:42:59.025 TheMove[95864:c07] foo

(lldb) po (void)NSLog(@"foo")
2013-06-19 14:43:10.758 TheMove[95864:c07] foo

If you can live with the nil (I can) it's faster to type and easier to remember just the po

Upvotes: 8

auco
auco

Reputation: 9579

You can use NSLog statements with breakpoints using "Debugger Command", but you need to add "expr" 

expr (void)NSLog(@"The Person Name is %@", p.name)

-

using expr command with a Debugger Command as breakpoint in Xcode 4.4

Upvotes: 28

cescofry
cescofry

Reputation: 3704

I ended up using 2 different actions for the same breakpoint. First a Log and then a debugger command with po varName. Only downside it will print in 2 different rows.

enter image description here

Upvotes: 5

Jason Coco
Jason Coco

Reputation: 78353

There are a couple of things you can do. Add a Log function from the drop-down, then add another box and select Debugger Command and enter po f.name.

If you want your log to be more complicated, you could do something more like this:

the person name is: @(const char *)[(NSString*)[p.name description] UTF8String]@

You best bet is probably to just use the debugger's graphical interface to watch variables. If you want to log messages, use NSLog.

Upvotes: 20

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