Difference between revisions of "Objective-C"
From Wikicliki
(→NSLog) |
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String Formatters for the trace/nslog: | String Formatters for the trace/nslog: | ||
− | === Hello World === | + | ==== Hello World ==== |
NSLog(@"Hello World!"); | NSLog(@"Hello World!"); | ||
− | + | ==== Debugging Variables ==== | |
− | === Debugging Variables === | ||
<pre>NSLog(@" a %% b = %i", c) | <pre>NSLog(@" a %% b = %i", c) | ||
c = b % a;</pre> | c = b % a;</pre> |
Revision as of 09:27, 21 February 2013
Objective-C is a superset of C language and it is called objective-c because it is a object-oriented language.
Contents
What one needs in order to program in Objective-C
- Source Code Editor (Xcode)
- Compiler (Xcode)
- Program to design the interface (Interface Builder - which is now built into Xcode)
- Debuggers (Instruments)
Get Xcode
Basics
Data types in Objective-C
- int (integer)
- unsigned int
- float (floating point number)
- double (double precision)
- char (a, b, c)
- string ("a string")
- bool (true/false)
Initialisation
- int myInteger;
- int myInteger = 42;
- int myInteger, myInteger2, myInteger3;
Operators
- operators - as normally expected except there is also "modulo"
- % - result will be the remainder from the integer division of the 1st by the 2nd
- (only for int or long, insert some caveat here about floats and doubles and using fmod)
- eg: int moduloResult = a % b;
NSLog
String Formatters for the trace/nslog:
Hello World
NSLog(@"Hello World!");
Debugging Variables
NSLog(@" a %% b = %i", c) c = b % a;
int myNum = 7; NSString *myString = @"Dog"; NSLog(@"The number is %i and the string is %@.", myNum, myString);
If you want a % sign you have to put in %%.
NSLog(@"%@", [NSNumber numberWithInt:i]); %@ Object %d, %i signed int %u unsigned int %f float/double %1.2f to specific number of decimals %x, %X hexadecimal int %o octal int %zu size_t %p pointer %e float/double (in scientific notation) %g float/double (as %f or %e, depending on value) %s C string (bytes) %S C string (unichar) %.*s Pascal string (requires two arguments, pass pstr[0] as the first, pstr+1 as the second) %c character %C unichar %lld long long %llu unsigned long long %Lf long double