Clear unwanted symbols

Questions
1

Hi,

I want to clear all symbols but i want to keep just J and GradientDescent in this group.

?Global`*

 Global`
A	i	n	x	x4	\[Alpha]$	$3	$8
bfp	J	n$	X	X$	\[Theta]	$4	
cp	lp	predict1	x1	y	\[CapitalTheta]	$5	
ex1data1	m	predict2	x2	y$	\[Theta]$	$6	
GradientDescent	m$	sf	x3	\[Alpha]	\[CapitalTheta]$	$7

Is there a clever way to achieve this rather than use

ClearAll[A, i, n, …]

Thanks

2

ClearAll @@ DeleteCases[Names[“Global`*”], “GradientDescent” | “J”]

ps. It is not really a good idea to use variables that start with UpperCase letter.

3

Oh, it’s brillant. Thanks!

For the upper case letter, it’s just a convention, not an obligation :P.