Control Statements and Loops in Objective-C

In programming, as in life, you have to make decisions and act on them. Objective-C provides control statements and loops to help your program take action. You may want to repeat a set of instructions based on some condition or state, for example, or even change the program execution sequence. Here is the basic syntax for Objective-C control statements and loops.

if else

<b>if</b> (condition) {
  statement(s) if the condition is true;
  }
<b>else</b> {
  statement(s) if the condition is not true;
  }

for

<b>for</b> (counter; condition; update counter) {
  statement(s) to execute while the condition is true;
  }

for in

<b>for</b> (Type newVariable <b>in</b> expression ) {
<b> </b> statement(s); 
  }
or
Type existingVariable ;
for (existingVariable in expression) {
  statement(s);
  }

• *Expression is an object that conforms to the NSFastEnumeration protocol.

• An NSArray and NSSet enumeration is over content.

• An NSDictionary enumeration is over keys.

• An NSManagedObjectModel enumeration is over entities.

while

while (condition) { 
  statement(s) to execute while the condition is true 
  } 

do while

do {
  statement(s) to execute while the condition is true 
  } while (condition);

Jump statements

return ;

Stop execution and return to the calling function.

break;

Leave a loop.

continue;

Skip the rest of the loop and start the next iteration.

goto labelName;
...
labelName: 

An absolute jump to another point in the program (don't use it).

exit();

Terminates your program with an exit code.