They said before you can get into game programming you need
to study game designing? is that true...

Game Designing requires Computer Science as Major

Well actually you need to know the fundamentals of game design to begin pogramming. You need to fully understand how a game should be constructed and why. This includes the way it is organized and what elements should perform a specific task.

if u asks me i would tell u it depends how good and big is ur game, if u r going to make 2 players tic tac or guess what is the number between 1-20 3 times this won't need any design effort.

it depends on which language and the game idea, when u say "i will make a game" what do u mean ? a simple window game that take the user 3 minutes to finish or a huge game like Half-Life ? well big games like doom quake needs big teams time and budget , so as one programmer don't even think about to reach that level.

as one programmer you can make simple games like tank ( a tank that move and shoot other tanks, some weapons and bonuses) or a small platform game or even an aim and shoot game that use mouse listener, programing small games like these is a good way to learn how to handle and solve small problems.

if you wanna make a bigger game that needs some effort with a story and new stile of gaming lets say a strategy game like C&C but much simpler, in that case yes u will need some designing before start coding cause if u code immediately your code will be in huge mess, but if u design how the game will look like , for example :-

1) game general description : here u can review the game name and overview of it and how to play it like:
a 2D strategy game witch can be played single player only with 3 modes ( blah blah blah) and it has two race, in game u can ......

2) classes names : here u can mention class and methods names and small description to see over view of all the code and how ur code will be look like , for example :

class Building : describe a building
class GUnit : (game unit) describe a simple unit like tank or solder
class Fire: describe a fire shoot
class Player: describe a player in the current game and it has arrays for his building units and fires .....

3) more detailed classes : here u describe the classes in more details and some methods in it and why u made it like that , for example :

class building
public :
string BName ... ;
int location, owner, HP .......; // owner refer to which player own it

4) game overview : like describing the story and the levels and what the player will get throw or missions .

u see when u make a design for ur game it will make coding it much easier because in design u can discover some problems much earlier and you will fix it in time which will make ur work more organize , but if u code a big game immediately it will be hard to catch some kind of errors for example which class is responsible for which methods.

well u can try out to make ur own way to design ur game or start coding and discover how good to have a design in the hard way XD