# Local variable x may not have been initialized
**URL:** https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477
**Category:** Beginners
**Created:** [October 6, 2019, 6:41pm UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477 "2019-10-06T18:41:47Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@FilDomInteractive](https://discourse.processing.org/u/FilDomInteractive)
#### Post date: [October 6, 2019, 6:41pm UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/1 "2019-10-06T18:41:47Z")
I’m completely new to processing, i’m making a calculator. Please help me!
* * *
```auto
boolean selected = false;
float x;
float y; {
x = 0;
y = 0; }
void setup() {
smooth(8);
size(350,450);
selected = true;
}
void draw() {
noStroke();
noLoop();
background(0);
fill(181,183,183);
ellipse(50,160,50,50);
ellipse(125,160,50,50);
ellipse(200,160,50,50);
fill(255,142,0);
ellipse(275,160,50,50);
fill(32,30,28);
ellipse(50,235,50,50);
fill(32,30,28);
ellipse(125,235,50,50);
fill(32,30,28);
ellipse(200,235,50,50);
fill(255,142,0);
ellipse(275,235,50,50);
fill(32,30,28);
ellipse(50,310,50,50);
fill(32,30,28);
ellipse(125,310,50,50);
fill(32,30,28);
ellipse(200,310,50,50);
fill(255,142,0);//259
ellipse(275,310,50,50);
fill(32,30,28);
ellipse(50,385,50,50);
fill(32,30,28);
rect(50,360,75,50);
fill(32,30,28);
ellipse(125,385,50,50);
fill(255,142,0);
ellipse(201,385,50,50);
fill(255,142,0);
ellipse(276,385,50,50);
fill(0);
text("NO_INPUT",65646,787867569);
textSize(30);
fill(0);
text("7",41,173);
textSize(30);
fill(0);
text("8",116,173);
textSize(30);
fill(0);
text("9",191,173);
textSize(30);
fill(255);
text("/",266,173);
textSize(30);
fill(255);
text("4", 41,248);
textSize(30);
fill(255);
text("5", 116,248);
textSize(30);
fill(255);
text("6", 191,248);
textSize(30);
fill(255);
text("X", 266,248);
textSize(30);
fill(255);
text("1", 41,323);
textSize(30);
fill(255);
text("2", 116,323);
textSize(30);
fill(255);
text("3", 191,323); //305
textSize(30);
fill(255);
text("-", 266,323);
textSize(30);
fill(255);
text("0", 41,398);
textSize(30);
fill(255);
text("+", 191,398);
textSize(30);
fill(255);
text("=", 266,398); //16,18
textSize(30);
}
void mousePressed() {
if(mousePressed) {
if(mouseX > 250 && mouseY > 380) {
print("=");
}
if(mousePressed) {
if(mouseX > 175 && mouseY > 380) {
print("+"); }
if(mousePressed) {
if(mouseX > 25 && mouseY > 380) {
print("0");
}
if(mousePressed) {
if(mouseX > 250 && mouseY > 305) {
print("-");
String data = "-";
print(x - y);}
if(mousePressed) {
if(mouseX > 175 && mouseY > 305) {
print("3");
float x = 3;
}
if(mousePressed) {
if(mouseX > 125 && mouseY > 305) {
print("2");
float x = x + 2;
}
if(mousePressed) {
if(mouseX > 25 && mouseY > 305) {
print("1");
float x = x + 1;
selected = true;
if(mousePressed) {
if(mouseX > 25 && mouseY > 305) {
if(selected = true) {
float y = y + 1;}
}
}
}
}}}}}}}}
```
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [October 6, 2019, 6:52pm UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/2 "2019-10-06T18:52:52Z")
> [@FilDomInteractive](#):
>
> float x;
> float y; {
> x = 0;
> y = 0; }
This won’t work
Say float x=0;
And leave away the brackets
---
### Author:  [@GoToLoop](https://discourse.processing.org/u/GoToLoop)
#### Post date: [October 6, 2019, 6:58pm UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/3 "2019-10-06T18:58:14Z")
1. `float x = x + 2;` -\> `x += 2;`
2. `float x = x + 1;` -\> `++x;`
3. `float y = y + 1;` -\> `++y;`
---
### Author:  [@GoToLoop](https://discourse.processing.org/u/GoToLoop)
#### Post date: [October 6, 2019, 10:05pm UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/4 "2019-10-06T22:05:10Z")
> [@Chrisir](#):
>
> And leave away the brackets.
Those brackets form an initialization block. And it is valid Java syntax. ☕
Although I’d just go w/ `float x, y`. Which already initializes both fields w/ `0.0f`. 😛
---
### Author:  [@FilDomInteractive](https://discourse.processing.org/u/FilDomInteractive)
#### Post date: [October 7, 2019, 12:09am UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/5 "2019-10-07T00:09:51Z")
Still doesn’t work 😕
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [October 7, 2019, 7:59am UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/6 "2019-10-07T07:59:00Z")
Can you please post your entire code
---
### Author:  [@Waboqueox](https://discourse.processing.org/u/Waboqueox)
#### Post date: [October 7, 2019, 8:57am UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/7 "2019-10-07T08:57:06Z")
Well, in order to be a little bit more readable I have formatted a little bit your code:
```auto
boolean selected = false;
float x=0;
float y=0;
void setup() {
smooth(8);
size(350,450);
selected = true;
textSize(30);
textAlign(CENTER);
}
void draw() {
noStroke();
noLoop();
background(0);
fill(181,183,183);
ellipse(50,160,50,50);
ellipse(125,160,50,50);
ellipse(200,160,50,50);
fill(32,30,28);
ellipse(50,235,50,50);
ellipse(125,235,50,50);
ellipse(200,235,50,50);
ellipse(50,310,50,50);
ellipse(125,310,50,50);
ellipse(200,310,50,50);
ellipse(50,385,50,50);
rect(50,360,75,50);
ellipse(125,385,50,50);
fill(255,142,0);//259
ellipse(275,160,50,50);
ellipse(275,235,50,50);
ellipse(275,310,50,50);
ellipse(201,385,50,50);
ellipse(276,385,50,50);
fill(0);
text("NO_INPUT", 150,30);//,65646,787867569);
text("7",50,160+10);
text("8",125,160+10);
text("9",200,160+10);
fill(255);
text("/",275,160+10);
text("4", 50,235+10);
text("5", 125,235+10);
text("6", 200,235+10);
text("X", 275,235+10);
text("1", 50,310+10);
text("2", 125,310+10);
text("3", 200,310+10); //305
text("-", 275,310+10);
text("0", 50,385+10);
text("+", 200,385+10);
text("=", 275,385+10); //16,18
}
void mousePressed() {
if(mouseX > 250 && mouseY > 380) {
print("="); }
if(mouseX > 175 && mouseY > 380) {
print("+"); }
if(mouseX > 25 && mouseY > 380) {
print("0"); }
if(mouseX > 250 && mouseY > 305) {
print("-");
String data = "-";
print(x - y); }
if(mouseX > 175 && mouseY > 305) {
print("3");
x = 3; }
if(mouseX > 125 && mouseY > 305) {
print("2");
x += 2; }
if(mouseX > 25 && mouseY > 305) {
print("1");
x ++;
selected = true;
if(mouseX > 25 && mouseY > 305) {
if(selected == true) {
y ++; }
}
}
}
```
> @FilDomInteractive Still doesn’t work 😕
What doesn’t work? 😅 😅
There are a lot of things that I suppose are not working, but go in order… for example, this is important and I fixed in the code; use:
` if(variable == 0)...` (here you are comparing the value of the variable)
instead of
` if(variable = 0)...` ( here you are giving a new value)
I haven’t check very in detail, but you had several times “float x = x + 1” or similar things, if you want to give x a new value, don’t use float in front (you are creating a new variable) use “x = x +1;” or what is better “x++;” or “x +=1;”
And finishing by now, if you want to use the “buttons” you have to specify the area better; example:
```auto
if(mouseX > 25 && mouseX < 75 && mouseY > 305 && mouseY < 355)
```
and for free; better to use " if {…}else if{…}else if{…}… " to spend less time comparing “ifs” if you want just one case of them.
Hope this helps you, and you can fix more things 😃
See you 🚨
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [October 7, 2019, 11:34am UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/8 "2019-10-07T11:34:40Z")
that’s for 33-3 =
and 33 + 3 =
(The other buttons don’t work yet)
Chrisir
```auto
boolean selected = false;
int x=0;
int y=0;
int bufferNum=0;
String command="";
void setup() {
size(350, 450);
smooth(8);
selected = true;
textSize(30);
textAlign(CENTER);
}
void draw() {
background(0);
noStroke();
// noLoop();
showCalc();
}
// ---------------------------------------------------
void showCalc() {
//fill(181, 183, 183);
fill(32, 30, 28);
ellipse(50, 160, 50, 50);
ellipse(125, 160, 50, 50);
ellipse(200, 160, 50, 50);
fill(32, 30, 28);
ellipse(50, 235, 50, 50);
ellipse(125, 235, 50, 50);
ellipse(200, 235, 50, 50);
ellipse(50, 310, 50, 50);
ellipse(125, 310, 50, 50);
ellipse(200, 310, 50, 50);
ellipse(50, 385, 50, 50);
rect(50, 360, 75, 50);
ellipse(125, 385, 50, 50);
fill(255, 142, 0);//259
ellipse(275, 160, 50, 50);
ellipse(275, 235, 50, 50);
ellipse(275, 310, 50, 50);
ellipse(201, 385, 50, 50);
ellipse(276, 385, 50, 50);
fill(0);
fill(255);
text("Calculator: try 33-3=", 150, 30);//,65646,787867569);
textAlign(RIGHT);
text(bufferNum, width-30, 90);//,65646,787867569);
textAlign(CENTER); // restore default
fill(255);
text("7", 50, 160+10);
text("8", 125, 160+10);
text("9", 200, 160+10);
fill(255);
text("/", 275, 160+10);
text("4", 50, 235+10);
text("5", 125, 235+10);
text("6", 200, 235+10);
text("x", 275, 235+10-2);
text("1", 50, 310+10);
text("2", 125, 310+10);
text("3", 200, 310+10); //305
text("-", 275, 310+10);
text("0", 50, 385+10);
text("+", 200, 385+10);
text("=", 275, 385+10); //16,18
}
void mousePressed() {
if (mouseX > 250 && mouseY > 380) {
print("=");
y=bufferNum;
// eval command
switch(command) {
case "+":
bufferNum=x+y;
break;
case "-":
bufferNum=x-y;
break;
case "/":
//
break;
case "x":
//
break;
}//switch
x=0;
y=0;
} else if (mouseX > 175 && mouseY > 380) {
print("+");
x=bufferNum;
y=0;
bufferNum=0;
command = "+";
} else if (mouseX > 25 && mouseY > 380) {
print("0");
} else if (mouseX > 250 && mouseY > 305) {
print("-");
x=bufferNum;
y=0;
bufferNum=0;
command = "-";
//print(x - y);
} else if (mouseX > 175 && mouseY > 305) {
println("3***");
bufferNum = extend (bufferNum, "3");
} else if (mouseX > 125 && mouseY > 305) {
print("2");
x += 2;
} else if (mouseX > 25 && mouseY > 305) {
print("1");
x ++;
selected = true;
if (mouseX > 25 && mouseY > 305) {
if (selected == true) {
y ++;
}
}
}
}
int extend(int what_, String add_) {
String buffer1= trim(str(what_)) + add_;
int buffer2 =int(buffer1);
println(buffer1);
return buffer2;
}
//
```
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [October 9, 2019, 1:57pm UTC](https://discourse.processing.org/t/local-variable-x-may-not-have-been-initialized/14477/9 "2019-10-09T13:57:22Z")
**Additionally:**
**object oriented programming**
You might want to look into object oriented programming. Thus you would have a new type (a class) Button that “represents” one button. Then you could have a list (array) of your buttons and for loop over it. Cool.
Each button would have its position (x and y), its text (“8”) and its command ("+", “-”…) but also functions like display() or mouseIsOver() all in one package.
That would make positioning and checking if the mouse is on the button much easier.
Please see [https://www.processing.org/tutorials/objects/](https://www.processing.org/tutorials/objects/)
**checking the mouse**
For checking mouse you could also use `dist()` (instead of `if(mouseX<....&&mouseY<...)` )
```auto
if(dist(buttonX,buttonY, mouseX,mouseY) < 20) {
....
}
```
Chrisir