javascript exiting for loop without returning

You're looking for the break statement.

Either use a break or continue statement

function MyFunction() { 
  for (var i = 0; i < SomeCondition; i++) { 

     if (i === SomeOtherCondition) { 

        // Do some work here 
        break;
     } 
  } 

  SomeOtherFunction(); 
  SomeOtherFunction2(); 
} 

Or to continue processing items except for those in a condition

function MyFunction() { 
  for (var i = 0; i < SomeCondition; i++) { 

     if (i != SomeOtherCondition) continue;

     // Do some work here 
  } 

  SomeOtherFunction(); 
  SomeOtherFunction2(); 
} 

Several people have offered break as the solution, and it is indeed the best answer to the question.

However, just for completeness, I feel I should also add that the question could be answered while retaining the return statement, by wrapping the contents of the if() condition in a closure function:

function MyFunction() {

  for (var i = 0; i < SomeCondition; i++) {

     if (i === SomeOtherCondition) {
        function() {
           // Do some work here
           return false;
        }();
     }
  }

  SomeOtherFunction();
  SomeOtherFunction2();
}

As I say, break is probably a better solution in this case, as it's the direct answer to the question and the closure does introduce some additional factors (such as changing the value of this, limiting the scope of variables introduced inside the function, etc). But it's worth offering as a solution, because it's a valuable technique to learn, if not necessarily to be used in this particular occasion then certainly for the future.