如何在Objective-C中打印不同類型的數據類型？

Question

我想打印所有類型的值，如char，long ...等等，還有nsdate，nsdictionary，frame ....我現在想打印每個類型變量的值。

Answer 1

基本類型，如整數，浮點，雙，等可以在它們被打印在C相同的方式進行打印，使用printf，fprintf，等等。如果需要打印你可以經常使用NSObject類的數據的方法(NSString *)description以獲得表示對象的數據的NSString。下面是一個例子...

#import <Foundation/Foundation.h> 

int main (int argc, const char * argv[]) { 
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; 

    NSString *string = [NSString stringWithFormat:@"Hello World!"]; 
    NSDate *date = [NSDate dateWithTimeIntervalSinceNow:0]; 
    NSArray *array = [NSArray arrayWithObject:@"Hello There!"]; 

    char *c_string = "Familiar ol' c string!"; 
    int number = 3; 

    printf("C String: %s\n",c_string); 
    printf("Int number: %u\n", number); 
    //In 10.5+ do not use [NSString cString] as it has been deprecated 
    printf("NSString: %s\n", [string UTF8String]); 
    printf("NSDate: %s\n", [date.description UTF8String]); 
    printf("NSArray: %s\n", [array.description UTF8String]); 

    //If you are using this information for debugging, it's often useful to pass the object to NSLOG() 

    NSLog(@"NSArray *array = \n%@", array); 

    [pool drain]; 
    return 0; 
} 

編輯：我認爲這將有助於看到輸出當例子跑了......

C String: Familiar ol' c string! 
Int number: 3 
NSString: Hello World! 
NSDate: 2010-03-12 01:52:31 -0600 
NSArray: (
    "Hello There!" 
) 
2010-03-12 01:52:31.385 printfTest[2828:a0f] NSArray *array = 
(
    "Hello There!" 
)