What is NSLog in Objective C?
NSLog outputs the date, time, process name, process ID, and thread ID in addition to the log message. printf just outputs the message. NSLog requires an NSString and automatically adds a newline at the end. printf requires a C string and does not automatically add a newline.
Where can I find NSLog output?
NSLog() output on the simulator does indeed show up in the Console Mac OS X application. Go to All Messages and then filter based on your app name to get rid of the fluff, and run again. You’ll see it in your output if the NSLog code is actually being hit during the execution of your program.
How do you print an integer value in Objective C?
Printing Variables
- int main (int argc, const char * argv[]) {
- NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
- int result;
- result = 10 + 20;
- NSLog(@”The sum of 10 and 20 is %i”, result);
- result = 25 – 30;
- NSLog(@”The difference between 25 and 30 is %i”, result);
- result = 8 * 9;
How do you print a Boolean value in Objective C?
There is no format specifier to print boolean type using NSLog. One way to print boolean value is to convert it to a string. Another way to print boolean value is to cast it to integer, achieving a binary output (1=yes, 0=no).
What is NSLog in Swift?
NSLog : NSLog adds a timestamp and identifier to the output, whereas print will not; NSLog statements appear in both the device’s console and debugger’s console whereas print only appears in the debugger console.
How do I print a string in Objective C?
You can use %@ for all objects including NSString. This will in turn call the objects description method and print the appropriate string. Most objects have a rather useful representation already there (e.g. NSArray objects return the descriptions of all their contents).
How do you concatenate strings in Swift?
String values can be added together (or concatenated) with the addition operator ( + ) to create a new String value:
- let string1 = “hello”
- let string2 = ” there”
- var welcome = string1 + string2.
- // welcome now equals “hello there”
What are the 4 boolean operators?
Boolean operators are specific words and symbols that you can use to expand or narrow your search parameters when using a database or search engine. The most common Boolean operators are AND, OR, NOT or AND NOT, quotation marks “”, parentheses (), and asterisks *.
How do you concatenate two variables in Swift?
Swift strings are represented by the String type….String values can be added together (or concatenated) with the addition operator ( + ) to create a new String value:
- let string1 = “hello”
- let string2 = ” there”
- var welcome = string1 + string2.
- // welcome now equals “hello there”
Is NSLog an Objective-C function?
The Objective-C language sits on top of C, so you will find both styles in most apps. Show activity on this post. As I understand it, NSLog isn’t an Objective C function but a C function built into the foundation of Cocoa.
What is the use of NSString in Objective C?
Like NSNumber, NSString is also immutable type. It’s used to represent text in Objective-C. NSString provides built-in support for Unicode, which means that we can include UTF-8 characters directly in string literals. stringWithFormat: class method is useful for generating strings that are composed of variable values.
Why is the NSLog method not available in Core Foundation?
The main reason is that the NSLog method, like many others in Core Foundation, is a C-based API, rather than an Objective-C API. C-style functions look like this myFunction (myParameter1, myParameter2).
Where can I find console output in NSLog?
Console output can appear in a number of places including (but not limited to) Xcode and the Console app. For more information about finding the console output from your app’s calls to NSLog, please see Technical Q&A QA1747: Debugging Deployed iOS Apps.