# Create randomly placed circles loop not working(runtime error)
**URL:** https://discourse.processing.org/t/create-randomly-placed-circles-loop-not-working-runtime-error/11719
**Category:** Coding Questions
**Created:** [May 30, 2019, 8:12pm UTC](https://discourse.processing.org/t/create-randomly-placed-circles-loop-not-working-runtime-error/11719 "2019-05-30T20:12:18Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@dakito](https://discourse.processing.org/u/dakito)
#### Post date: [May 30, 2019, 8:12pm UTC](https://discourse.processing.org/t/create-randomly-placed-circles-loop-not-working-runtime-error/11719/1 "2019-05-30T20:12:18Z")
So I am making a game where you would click on randomly appearing circles, and for the sake of reusability and self-improvement I have chosen to use for loops and arrays for the first time.
After some unexpected results I have gotten this piece of code, and I have no idea what is causing it to completely not work.
The game would look like
[aimbooster.com](http://aimbooster.com)
```auto
float fRandomX,fRandomY;
int randomX, randomY;
void game() {
currentColor=colors[1];
for (int i=0; i==4; i++) {
fRandomX=random(20, 580);
fRandomY=random(20, 580);
randomX=round(fRandomX);
randomY=round(fRandomY);
targetX[i]=randomX;
targetY[i]=randomY;
}
for (int i = 0; i ==4; i++) {
ellipse(targetX[i], targetY[i], size/2.0, size/2.0);
}
}
```
If that Is not enough code,
```auto
int size=40, difficulty;
float targetDelay;
boolean hasStarted, hasLost, menuState, gameState;
int currentColor; // color system
int[] colors={#264653,#2A9D8F,#E9C46A,#F4A261};
int[] targetX, targetY;
int lastScore;
void setup(){
ellipseMode(CENTER);
rectMode(CORNERS);
size(600,600);
frameRate(60);
}
void draw(){
background(currentColor);
check();
debug();
}
void check(){
if(!hasStarted ||hasLost){
menuState=true; //run the menu
hasStarted=true; //dont run it again
hasLost=false; //reset game if lost
}
if(menuState){
menu(lastScore);
}else if(gameState){
game();
}
}
void menu(int score1){
currentColor=colors[0];
ellipse(100,100,30,30);//gameButton
text("last Score:"+score1,50,50);
}
void mousePressed(){
if(dist(mouseX,mouseY,100,100)<30){
gameState=true;
menuState=false;
}
}
void debug(){
text(mouseX+";"+mouseY,20,20);
}
```
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [May 30, 2019, 8:41pm UTC](https://discourse.processing.org/t/create-randomly-placed-circles-loop-not-working-runtime-error/11719/2 "2019-05-30T20:41:44Z")
not much better…
```auto
int size=40, difficulty;
float targetDelay;
boolean hasStarted=false, hasLost=false, menuState=true, gameState=false;
int currentColor; // color system
int[] colors={#264653, #2A9D8F, #E9C46A, #F4A261};
int[] targetX=new int[4], targetY=new int[4];
int lastScore;
float fRandomX, fRandomY;
int randomX, randomY;
//-------------------------------------------------------------------------
void setup() {
size(600, 600);
ellipseMode(CENTER);
rectMode(CORNERS);
frameRate(1);
}
void draw() {
background(currentColor);
check();
debug();
}
//-------------------------------------------------------------------------
void check() {
if (!hasStarted ||hasLost) {
menuState=true; //run the menu
hasStarted=true; //dont run it again
hasLost=false; //reset game if lost
}
if (menuState) {
menu(lastScore);
} else if (gameState) {
game();
}
}
void game() {
currentColor=colors[1];
for (int i=0; i<4; i++) {
fRandomX=random(20, 580);
fRandomY=random(20, 580);
randomX=round(fRandomX);
randomY=round(fRandomY);
targetX[i]=randomX;
targetY[i]=randomY;
}
for (int i = 0; i<4; i++) {
fill(colors[i]);
ellipse(targetX[i], targetY[i],
size/2.0, size/2.0);
}
}
void menu(int score1) {
currentColor=colors[0];
ellipse(100, 100, 30, 30);//gameButton
text("last Score:"+score1, 50, 50);
}
void mousePressed() {
if (dist(mouseX, mouseY, 100, 100)<30) {
gameState=true;
menuState=false;
}
}
void debug() {
text(mouseX+";"+mouseY, 20, 20);
}
//
```
---
### Author:  [@dakito](https://discourse.processing.org/u/dakito)
#### Post date: [May 31, 2019, 7:26pm UTC](https://discourse.processing.org/t/create-randomly-placed-circles-loop-not-working-runtime-error/11719/3 "2019-05-31T19:26:47Z")
The nullpointer error was happening because of the array not having a max amount of elements.
```auto
int[] targetX= new int[10], targetY=new int[10];
```
Now the problem lies in the fact that the circles are moving too fast. I have no idea on how to slow down a for loop or maybe even not change the coordinates if the circle has not been clicked yet. I will make them clickable after I find out how to make them not disappear instantly.
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [May 31, 2019, 10:39pm UTC](https://discourse.processing.org/t/create-randomly-placed-circles-loop-not-working-runtime-error/11719/4 "2019-05-31T22:39:34Z")
here is a timer
```auto
int size=40, difficulty;
float targetDelay;
boolean hasStarted=false, hasLost=false, menuState=false, gameState=true;
int currentColor; // color system
int[] colors={#264653, #2A9D8F, #E9C46A, #F4A261};
int[] targetX=new int[4],
targetY=new int[4];
int lastScore;
float fRandomX, fRandomY;
int randomX, randomY;
int timer;
boolean firstTime=true;
//-------------------------------------------------------------------------
void setup() {
size(600, 600);
ellipseMode(CENTER);
rectMode(CORNERS);
frameRate(99);
timer=millis();
}
void draw() {
background(currentColor);
check();
debug();
}
//-------------------------------------------------------------------------
void check() {
if (!hasStarted ||hasLost) {
menuState=true; //run the menu
hasStarted=true; //dont run it again
hasLost=false; //reset game if lost
}
if (menuState) {
menu(lastScore);
} else if (gameState) {
game();
}
}
void game() {
currentColor=colors[1];
// timer
if (millis()-timer > 3500 || firstTime) {
// define
for (int i=0; i<4; i++) {
fRandomX=random(20, 580);
fRandomY=random(20, 580);
randomX=round(fRandomX);
randomY=round(fRandomY);
targetX[i]=randomX;
targetY[i]=randomY;
}
timer=millis();
firstTime=false;
}
// show
for (int i = 0; i<4; i++) {
fill(colors[i]);
ellipse(targetX[i], targetY[i],
size/2.0, size/2.0);
}
}
void menu(int score1) {
currentColor=colors[0];
ellipse(100, 100, 30, 30);//gameButton
text("last Score:"+score1, 50, 50);
}
void mousePressed() {
if (dist(mouseX, mouseY, 100, 100)<30) {
gameState=true;
menuState=false;
}
}
void debug() {
text(mouseX+";"+mouseY, 20, 20);
}
//
```