why won't my character move

Question

I am using game maker because I am new to game development and I think it's the easiest to understand because I took a course on it but I put in all the events so that my playerobj moves when you press the A and D keys but when I load up the game it doesn't work here is the GML code below that I am using:

//Speed of player: 5 Pixels per frame
 playerSpeed = 5;

 //Shortcuts for keypresses
 MOVELEFT = keyboard_check(ord('A'));
 MOVERIGHT = keyboard_check(ord('D'));
 MOVEUP = keyboard_check(ord('W'));
 MOVEDOWN = keyboard_check(ord('S'));

 //Move Player
 if (MOVELEFT && x > sprite_width/2) 
 { 
x -= playerSpeed; 
 }

 if (MOVERIGHT && x < room_width - sprite_width/2) 
 { 
x += playerSpeed; 
 }

 if (MOVEUP && y > room_height/2) 
 { 
y -= playerSpeed; 
 }

 if (MOVEDOWN && y < room_height - sprite_width/2) 
 { 
y += playerSpeed; 
 }

Answer 1

Your player isn't moving because you associated this very code to the wrong instance event. Try this:

Create Event

/// Declare variables
playerSpeed = 5;    // 5 pixels per step
MOVELEFT = 0;       // Checks "A" presses
MOVERIGHT = 0;      // Checks "D" presses
MOVEUP = 0;         // Checks "W" presses
MOVEDOWN = 0;       // Checks "S" presses

Declaration of all variables is important for operations, as it's good practice to not let an assignment in further events be treated as a declaration too.

Step Event

///Move player
if ( (MOVELEFT) && (x>sprite_width/2) )
{
    x -= playerSpeed;
}

if ( (MOVERIGHT) && (x<room_width-sprite_width/2) )
{
    x += playerSpeed;
}

if ( (MOVEUP) && (y>room_height/2) )
{
    y -= playerSpeed;
}

if ( (MOVEDOWN) && (y<room_height-sprite_width/2) )
{ 
    y += playerSpeed;
}

You need to put this part of code in the instance's Step Event in order to check keys continuously and move your player every step accordingly. This should work fine.