Shell Programming and Scripting

sub test{
	return (2,3,4,5,6,3,4,50);
}

($a,$b)=(test)[1,4]; # 3,6

($a,$b)=test[1,4]; # 2,3

($a,$b)=(test)[1,4]; # 3,6
In the above statement it calls the function test, and takes the
return value of test as an array and return its 1st and 4th indexes.
so you are getting 3 and 6

($a,$b)=test[1,4]; # 2,3
In the above statement, it calls the function and returns the
array. since you assigned the return values to two scalar
you are getting first two index of array.

Here there is no meaning of giving [1,4].

You just try the following you will understand:
($a,$b)= test => will give 2 and 3
($a,$b)= test[4,5] => will give 2 and 3
It will give only 0 and 1st index irrespective of index 
you give here.