如何在Objective-C中打印不同类型的数据类型？

Question

我想打印所有类型的值，如char，long ...等等，还有nsdate，nsdictionary，frame ....我现在想打印每个类型变量的值。

Answer 1

基本类型，如整数，浮点，双，等可以在它们被打印在C相同的方式进行打印，使用printf，fprintf，等等。如果需要打印你可以经常使用NSObject类的数据的方法(NSString *)description以获得表示对象的数据的NSString。下面是一个例子...

#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; 
} 

编辑：我认为这将有助于看到输出当例子跑了......

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!" 
)