Blog

Method does not exist or incorrect signature

handle method goes not exist or incorrect signature
handle method goes not exist or incorrect signature

In most of the cases Incorrect signature means you are passing invalid parameter to the method. In this blog we have discussed some common scenario of getting error – method does not exist or incorrect signature .

Scenario - 1

error – Method does not exist or incorrect signature: void emptyRecycleBin(Id) from the type Database
error – Method does not exist or incorrect signature: void emptyRecycleBin(String) from the type

Solution

Here you are trying to pass string or Id to the Database.emptyRecycleBin. Supported parameter for emptyRecycleBin are  

Sample Code​

				
					Database.emptyRecycleBin(Trigger.old); 
				
			
				
					Account con = new Account(Id = '0015j00000nSCGY');
Database.emptyRecycleBin(con);
				
			
				
					List<Account> deletedAcc = [SELECT Id from Account where isDeleted=true ALL ROWS];
Database.emptyRecycleBin(deletedAcc);

Here you can find official documentation for Database.emptyRecycleBin.

What the error means

The compiler cannot find a method with that name that accepts the types and the number of values you passed. The message shows the signature it tried to find, for example void emptyRecycleBin(Id), which tells you the argument type it saw.

Other common causes

  • Wrong argument type: Math.max('1', '2') fails because max accepts numbers, not strings.
  • Wrong number of arguments: Date.newInstance(2025, 1) fails because newInstance needs year, month and day.
  • Wrong method name or spelling: a small typo such as isEmpty written as isEmtpy.
  • Static versus instance: calling an instance method on the class name, or the other way round.
  • Single record where a list is needed, or the reverse: some methods take only a list.

How to fix it

  1. Read the signature in the error message and compare it with the Apex reference documentation of the class.
  2. Check the type of each variable you pass, for example with System.debug(value).
  3. Convert the value when needed, for example Integer.valueOf(text).
  4. Check spelling and static or instance use.

FAQ

Is this a runtime or a compile error?
It is a compile error. It appears when you save the class, before any code runs.

Does the API version matter?
Sometimes. A new method may be missing in a class that uses a very old API version. Update the version of the class.

Leave a Reply