Objective-C 程序设计（第六版）第二章习题答案

1.略

2.

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{

    @autoreleasepool {

        // insert code here...

       NSLog(@"In Obiective-c, lowercase letters are significance .\n main is where program execution begins.\n Open and closed brace enclose program stateme               nts in a routine .\n All program statements must be terminated by a semicolon .");

}

return 0;

}

3.

    testing...

    .... 1

    ... 2

    .. 3

4.

 int value1, value2, sum;
         value1 = 87;
 value2 = 15;
 sum = value1 - value2;
 NSLog(@"sum is %i", sum);

5.改正后的程序

  int sum;                               <---原文INT改为int.
  /* COMPUTE RESULT*/                    <---原文右注释号//改为*/.
  sum = 25+37-19;                        <---原文后加分号结束.
  /* DISPLAY RESULTS*/                   <---原文注释号改为/*..*/或//.
  NSLog(@"The answer is %i",sum);        <---原文改为双引号，加上sum前的逗号.

6.

The result is 95.

END