Hi,

Lets assume that you have a method to update a Account record.

I am giving a snippet of code to cover try/catch block inside test method.

To cover a catch block, you need identify the situation when your code invoke the catch block.

For example, the situation where object instance is not found. Therefore in the test method, I have deleted the account instance that i created and once again invoke the save method.

Try this:

private final Account acc;

public pagereference save()
{
	try
	{
		update acc;
	}
	catch(Exception e)
	{
		// some code;
	}
}


// Test code

static testMethod void Test_AccounUpdate()
{
	test.startTest();
	
	Account testAcc=new Account(Name='Test Account');
	insert testAcc;

	
	// Create instance of standard controller if you are using
	ApexPages.StandardController con = new ApexPages.StandardController(testAcc);

	// Now you can create instance of a class and invoke controller method
	AccountUpdateController ext= new AccountUpdateController();

	ApexPages.Pagereference result = ext.save(); // This will cover try block

	delete a; // Delete account record to cover catch block

	result = ext.save();
	
	test.stopTest();
} // End of test method

 Hope this helps :)

Thanks,

Devendra