Difference between NSLog and Printf statement for ObjectiveC

Question

I want to know about the difference between the NSLog and the Printf statement in Objective-C (for application purpose...!)

Why do all developer use NSLog instead of Printf ?

Both look similar, but what is the difference in internal working?

At which point can they be differentiated ?

Solution 1

NSLog is like a printf, but it does a bit more:

• A timestamp is added to the output.
• The output is sent to the Xcode console, or whatever stderr is defined as.
• It accepts all the printf specifiers, but it also accepts the @ operator for objects which displays the string provided by the object's description method. (description is part of NSObject, so all objects can override it to return a string that describes the object).
• The output is also sent to the Apple System Log (ASL), which is Apple's version of syslogd. This data can be read by other applications using a C API, or by a OS X user using the application “Console”.

Solution 2

From a developer point of view, the biggest difference is that NSLog supports Objective-C object types via the %@ format. NSLog also writes to stderr, while printf writes to stdout.

Solution 3

I see two main differences between NSLog and printf:

1. NSLog supports NSString objects through the %@ extension;

2. furthermore, NSLog automatically adds time and process data (e.g., 2012-01-25 17:52:10.479 process[906:707])

Comments

[James Webster]

More accurately: NSLog supports objects through the %@ extension, by implicitly calling that object's -(NSString*) description; method

[Munim]

The third biggest difference is that NSLog sends output to stderr, where as printf sends to stdout.

[jxramos]

Question, is this Apple System Log synonymous with Unified Logging which appears to use the os_log construct.

[jxramos]

Apparently they're distinct as it turns out blog.safedk.com/technology/nslog-os_log-multiple-ios-version‌​s. bignerdranch.com/blog/…