Apex ternary operator - Error: Compile Error: Expression cannot be a statement

Question

Trying to simplify multifle if-else conditions . Below code is throwing error " Error: Compile Error: Expression cannot be a statement. " . Can you please let me know how to resolve the issue ?

 if (hasFailedBatches) {
   Boolean inDMode = run.Run_Mode__c == 'inDMode' ? true:false;
   inDMode ? input.put('Status', 'Failed'):input.put('Status', 'Retrival fialed');
 }

Answer 1

While:

inDMode ? input.put('Status', 'Failed'):input.put('Status', 'Retrival fialed');

is legal in JavaScript and other languages, you can't do this in Apex. Instead, you can use the ternary operator as a parameter:

input.put(
  'Status', 
  inDMode? 'Failed', 'Retrieval Failed'
);

Other Notes

You can also use a ternary operator with a compatible set of data types, such as:

(isInput? inputMap: outputMap).put('key','value');

And it's also legal for functions as long as they return the same type:

someVar = someBoolean? functionA(): functionB();

Note that a Boolean operator already returns a Boolean:

Boolean inDMode = run.Run_Mode__c == 'inDMode';