1:在JAVA语言里,你肯定定义一个返回值是String的函数(方法),肯定不要加上指针*标示。但是Objective--C就需要。
2:代码
#import <Foundation/Foundation.h> // returns No if the two integers have the same //value ,YES otherwise BOOL areIntsDifferent(int thing1,int thing2) { if (thing1 == thing2){ return (NO); } else { return (YES); } }//areIntsDifferent NSString *boolString(BOOL yesNo) { if(yesNo == NO){ return (@"NO"); } else { return (@"YES"); } }// boolString int main(int argc, const char * argv[]) { @autoreleasepool { // insert code here... BOOL areTheyDifferent; areTheyDifferent = areIntsDifferent(5, 5); NSLog(@"are %d and %d different? %@",5,5,boolString(areTheyDifferent)); areTheyDifferent = areIntsDifferent(23, 42); NSLog(@"are %d and %d different ? %@",23,42,boolString(areTheyDifferent)); } return 0; }
3:扩展
NSLog(@"are %d and %d different ? %@",23,42,boolString(areTheyDifferent));
在代码中%@是NSLog()的专用格式说明符,它支持将NSString的值插入到NSLog中。