Objective-C > Condition expression

• if - else-if - else statement:

#import < Foundation/Foundation.h> int main(int argc, const char * argv[]){     NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];     NSString *output = @"\n\n";     [output autorelease];     if ( 3 > 5) {         NSLog(@”3 is larger than 5”);     } else if (4 > 5) {         NSLog(@”4 is larger than 5”);     } else if (5 > 5) {         NSLog(@”5 is larger than 5”);     } else if (6 > 5) {         NSLog(@”6 is larger than 5”);     } else {         NSLog(@”None of the above can be accepted”);     }     output = [output stringByAppendingString: @"\n\n"];     NSLog(output);     [pool drain];     return 0; }

• switch ... case ... break ... default statement:

switch (6) {     case 3:         System.out.println("選擇是3...");         NSLog(@”cute3”);         break;     case 4:         System.out.println("選擇是4...");         NSLog(@”cute4”);         break;     case 5:         System.out.println("選擇是3...");         NSLog(@”cute5”);         break;     case 6:         System.out.println("選擇是6...");         NSLog(@”cute6”);         break;     default:        System.out.println("以上沒有符合的條件:");         NSLog(@”None cute”);         default;

• If no break within default, the logic inside default will be executed everytime.

#import <Foundtation/Foundation.h>int main (int argc, const char * argv[]){     NSAutoreleasePool *pool = [NSAutoreleasePool alloc] init];     NSString *output = @”\n\n”;     [output autorelease];     switch (6) {     case 3:         output = [output stringByAppendingString: @”Choice is 3...”];         break;     case 4:         output = [output stringByAppendingString: @”Choice is 4...”];         break;     case 5:         output = [output stringByAppendingString: @”Choice is 5...”];         break;     case 6:         output = [output stringByAppendingString: @”Choice is 6...”];         break;     default:         output = [output stringByAppendingString: @”Choice is default”];     }     output = [output stringByAppendingString: @”\n\n”];     NSLog(output);     [pool drain];     return 0; }

• while loop:
• Control variable i has to be defined before while loop.

int i = 10;     while (i>0){      System.out.println(i);      NSLog(i);      i--;  }

• for loop:

for (int i = 0; i > 0 ; i --){       output = [output stringByAppendingFormat: @"%i\n", i];  }

int i = i; for (; i> 0){     output = [output stringByAppendingFormat: @"%i\n", i]; }

• do-while loop: