Array causing NullPointerException error?

Processing Beginners
1

Hello everyone! Today, I’ve decided to start working on my game. I had some old code for player movement that I wanted to see if I could port over, and here it is. Unfortunately, it keeps throwing me a ‘NullPointerException’ error and crashing the sketch. If anyone could help me, please do!

int[] keys; //I TRIED BOOLEAN AS I THOUGHT IT WOULD WORK BETTER BUT NO DICE.
void keyPressed() {
  keys[keyCode] = 1; //IT ERRORS HERE
  //print(keyCode);
 // print(key);
}
void keyReleased() {
  keys[keyCode] = 0; //AND HERE
//AND BASICALLY ANYWHERE I CALL keys[]. 
}


void PlayerMovement() {
  if (keys[65] == 1 || keys[37] == 1) {
    accl.x-=ship_acc_amount;
  } else if (keys[68] == 1 || keys[39] == 1) {
    accl.x+=ship_acc_amount;
  }
  if (keys[87] == 1|| keys[38] == 1) {
    accl.y-=ship_acc_amount;
    //pship.y += tempy;
  } else if (keys[83] == 1 || keys[40] == 1) {
    accl.y+=ship_acc_amount;
  }
  //ON KEY PRESS, INCREASE THE PLAYER'S ACCELERATION BY THE ACCELERATION AMOUNT. 


  pship.x+=accl.x;
  pship.y+=accl.y; 
  //ADD THE ACCELERATION FORCE TO THE PLAYER

  //ENSURE SPEED CAP:
  if (keys[83] == 1 || keys[40] == 1 || keys[87] == 1 || keys[38] == 1 || keys[68] == 1 || keys[39] == 1 || keys[65] == 1 || keys[37] == 1) {
    //unimportant speed cap code
 }
};

Normally I would set the value of the keycode in the array to true, but it didn’t work so I tried an integer value instead. I think it could be that the value assigned is undefined? But I’m not too sure.

2

NEVERMIND! I wasn’t actually creating the array using the constructor method.
Here’s the new code, (and also the solution to my problem):

Boolean[] keys = new Boolean[150];
void keyPressed() {
  keys[keyCode] = true;
  //print(keyCode);
 // print(key);
}
void keyReleased() {
  keys[keyCode] = false;
}
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