### Author:  [@Thur](https://discourse.processing.org/u/Thur)
#### Post date: [February 5, 2021, 4:32pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/1 "2021-02-05T16:32:23Z")
# Hey. While working with an array of characters I checked the value of the array members by using the print / println function. The code boils down to :
# void setup() { char[] ch = new char[2]; ch[0] = ‘0’; ch[1] = ‘0’; print("two statements: "); println(ch[0] + ch[1]); println("one statement: " + ch[0] + ch[1]); exit(); }
# which on the console delivers:
# two statements: 96 one statement: 00
I am able to indicate the origine of the 96 as being twice de ASCII code of ‘0’ (zero) but the difference in behaviour remains strange. Although I can live with the phenomenon, to me it seems reasonable two have the print function work in both case in the same way.
Thur
---
### Author:  [@josephh](https://discourse.processing.org/u/josephh)
#### Post date: [February 5, 2021, 6:20pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/2 "2021-02-05T18:20:59Z")
Hi,
Welcome to the forum! 😉
Note that you can format your code by using the `` button when editing a message.
The fact you are seeing `96` is because the way Java handle conversion when using an operator :
>
> If any operand is of a reference type, it is subjected to unboxing conversion ([§5.1.8](https://docs.oracle.com/javase/specs/jls/se7/html/jls-5.html#jls-5.1.8)).
>
> - Widening primitive conversion ([§5.1.2](https://docs.oracle.com/javase/specs/jls/se7/html/jls-5.html#jls-5.1.2)) is applied to convert either or both operands as specified by the following rules:
>
> - If either operand is of type `double` , the other is converted to `double` .
>
> - Otherwise, if either operand is of type `float` , the other is converted to `float` .
>
> - Otherwise, if either operand is of type `long` , the other is converted to `long` .
>
> - **Otherwise, both operands are converted to type `int` .**
So when adding two `char`, they are converted to `int` so their UTF-16 code :
```auto
char ch1 = '0';
char ch2 = '0';
println(ch1 + ch2);
// -> 48 + 48 = 96
```
Now in the second print statement, you have **associativity**. For example the [associativity](https://www.w3adda.com/java-tutorial/java-operator-precedence-and-associativity) of the `+` operator is `left to right`.
It means that it first performs left operations and propagate to the right members of the expression so :
```auto
"one statement: " + ch[0] + ch[1] = ( ( "one statement: " + ch[0] ) + ch[1] )
```
But in that case, adding a string with an int gives you a string so you have :
```auto
( ( "one statement: " + ch[0] ) + ch[1] )
( "one statement: 0" + ch[1] )
"one statement: 00"
```
So this has nothing to do with the fact that the `char` are taken from an array.
Hope it helps 🙂
---
### Author:  [@paulgoux](https://discourse.processing.org/u/paulgoux)
#### Post date: [February 5, 2021, 6:31pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/3 "2021-02-05T18:31:47Z")
Try using a comma instead of the addition sign. The addition sign will add numbers when paired with other numbers, but will convert a number to a string if paired with a string, at least that’s my understanding.
```auto
void setup() {
char[] ch = new char[2];
ch[0] = '0';
ch[1] = '0';
print("two statements: ");
println(ch[0] + ch[1]);
println("one statement: ", ch[0] + ch[1]);
exit();
}
```
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [February 6, 2021, 12:24pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/4 "2021-02-06T12:24:19Z")
[paulgoux](https://discourse.processing.org/u/paulgoux)
hi
if you kind explain this for me
```auto
String msg = "<0,0>";
void drawSliderOne() {
pushStyle();
noStroke();
num_1 = map(loc_1, 0.0, width, 2, 10);
void drawSliderTwo() {
pushStyle();
noStroke();
num_2 = map(loc_2, 0.0, width, 2, 10);
void sendData() throws IOException {
msg = "<"+int(num_1)+","+int(num_2)+">";
```
```auto
String msg = "<0,0>"// the start and end delimiter < > what to add here "<0,0>" to send more
```
and what to add here ??
```auto
String msg = "<0,0>";
void drawSlider1() {
pushStyle();
noStroke();
num_1 = map(loc_1, 0.0, width, 2, 10);
void drawSlider2() {
pushStyle();
noStroke();
num_2 = map(loc_2, 0.0, width, 2, 10);
void drawSlider3() {
pushStyle();
noStroke();
num_3 = map(loc_3, 0.0, width, 2, 10);
void drawSlider4() {
pushStyle();
noStroke();
num_4 = map(loc_4, 0.0, width, 2, 10);
void drawSlider5() {
pushStyle();
noStroke();
num_5 = map(loc_5, 0.0, width, 2, 10);
void drawSlider6() {
pushStyle();
noStroke();
num_6 = map(loc_6, 0.0, width, 2, 10);
void sendData() throws IOException {
msg = "<"+int(num_1)+","+int(num_2)+">"; //how to add num_2 to num_6 here ?
```
what to add here
String msg = “\<0,0\>”;
and what add here
msg = “\<”+int(num\_1)+","+int(num\_2)+"\>"; //how to add num\_2 to num\_6 here ?
thank you
---
### Author:  [@paulgoux](https://discourse.processing.org/u/paulgoux)
#### Post date: [February 6, 2021, 2:07pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/5 "2021-02-06T14:07:31Z")
The comma can only be used in println or print, its a parameter separator, not a string separator.
```auto
//invalid
String s ="4","4";
```
```auto
//valid
String s ="4"+"4";
```
Although I would probably refrain from arithmetic in strings as I don’t fully understand how the numbers will come out. So perhaps keep arithmetic in its native integer or float the convert your answer to string. But that’s up to you.
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [February 6, 2021, 2:30pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/6 "2021-02-06T14:30:02Z")
> [@paulgoux](#):
>
> The comma
The comma here is delimiter
```auto
String msg = "<0,0>"
void sendData() throws IOException {
msg = "<"+int(num_1)+","+int(num_2)+">";
```
could be
```auto
String msg = "<0#0>"
void sendData() throws IOException {
msg = "<"+int(num_1)+"#"+int(num_2)+">";
```
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [February 6, 2021, 2:50pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/7 "2021-02-06T14:50:08Z")
[josephh](https://discourse.processing.org/u/josephh)
can you help ?
if you kind
---
### Author:  [@josephh](https://discourse.processing.org/u/josephh)
#### Post date: [February 6, 2021, 5:17pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/8 "2021-02-06T17:17:42Z")
Hi,
Can you please post some code that works? I suppose you are using Processing Java but there’s missing brackets and semicolons.
Also can you describe more precisely what is the goal of your program? (Because it’s difficult to understand with two sentences…) 😉
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [February 6, 2021, 5:32pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/9 "2021-02-06T17:32:13Z")
[josephh](https://discourse.processing.org/u/josephh)
this is working code
what i need is \>\> if i want to increase the slider from 2 to six what should i add here
}
void sendData() throws IOException {
**msg = “\<”+int(num\_1)+","+int(num\_2)+"\>";** in this line how to add from int(num\_3) to int(num\_6)
mmOutputStream.write(msg.getBytes());
}
this adding just what i want to code
int(num\_3)
int(num\_4)
int(num\_5)
int(num\_6)
```auto
import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Build.VERSION_CODES;
import processing.core.PConstants;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothSocket;
import android.content.Intent;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Set;
import java.util.UUID;
BluetoothAdapter mBluetoothAdapter;
BluetoothSocket mmSocket;
BluetoothDevice mmDevice;
OutputStream mmOutputStream;
InputStream mmInputStream;
Activity activity;
Permission bp, afl;
Thread runThread;
byte[] readBuffer;
int buffer_index;
int counter;
boolean stop_thread, plotting = false, init = true;
boolean drag_just_finished;
String msg = "<0,0>";
String device_name = "HC-05";
String r_str, t_str;
boolean permissions_granted;
float a, b;
float px_1, py_1, x_1, y_1, px_2, py_2, x_2, y_2;
float loc_1, loc_2, num_1 = 0, num_2 = 0;
String[] y_values = {"0#0"};
void setup() {
fullScreen();
orientation(LANDSCAPE);
bp = new Permission(this, "BLUETOOTH");
afl = new Permission(this, "ACCESS_FINE_LOCATION");
textAlign(CENTER);
textSize(70);
t_str = "Click to connect.";
textSize(12); // To create a "text width factor",
float twf = width/textWidth(t_str);
int f = 4; // Empericaly found
textSize(f*twf); // Making it proportional for other screen resolutions
loc_1 = width/50;
loc_2 = width/50;
}
void draw() {
if (plotting == false && init) {
background(150);
text(t_str, width/2, height/2);
strokeWeight(10);
noFill();
stroke(50);
rect(0, 0, width, height);
} else if (plotting == false) {
drawSliderOne();
drawSliderTwo();
}
}
void mousePressed () {
if (init) {
try {
init = false;
findBluetooth();
connect();
plotting = true;
fill(0, 0, 90);
rect(0, 0, width, height);
drawSliderOne();
drawSliderTwo();
}
catch (IOException ex) {
println(ex);
}
}
}
void mouseDragged() {
plotting = false;
if (mouseY > height-height/8) {
loc_1 = mouseX;
if (loc_1 < width/50) loc_1 = width/50;
if (loc_1 > width-width/50) loc_1 = width-width/50;
try {
sendData();
}
catch (IOException ex) {
}
}
if (mouseY > height-height/3 && mouseY < height-height/3+height/8) {
loc_2 = mouseX;
if (loc_2 < width/50) loc_2 = width/50;
if (loc_2 > width-width/50) loc_2 = width-width/50;
try {
sendData();
}
catch (IOException ex) {
}
}
}
void mouseReleased() {
plotting = true;
}
void drawSliderOne() {
pushStyle();
noStroke();
num_1 = map(loc_1, 0.0, width, 2, 10);
fill(100, 180, 200);
rect(0, height-height/8, width, height/8);
fill(200, 200, 255);
rect(width/50, height-height/16, width-width/25, height/100);
fill(100, 100, 255);
ellipse(loc_1, height-height/17, height/20, height/20);
popStyle();
}
void drawSliderTwo() {
pushStyle();
noStroke();
num_2 = map(loc_2, 0.0, width, 2, 10);
fill(100, 180, 200);
rect(0, height-height/3, width, height/8);
fill(200, 200, 255);
rect(width/50, height-9*height/32, width-width/25, height/100);
fill(100, 100, 255);
ellipse(loc_2, height-9*height/32, height/20, height/20);
popStyle();
}
void plot(String r_str) {
if (r_str.length() < 3 || r_str == null) r_str = "0#0";
if (plotting) {
y_values = split(r_str, "#");
stroke(0, 200, 255);
strokeWeight(2);
y_1 = int(y_values[0])+height/6;
line(px_1, py_1, x_1, y_1);
py_1 = y_1;
px_1 = x_1;
x_1++;
if (x_1 > width) {
x_1 = y_1 = px_1 = py_1 = x_2 = y_2 = px_2 = py_2 = 0;
fill(0, 0, 90);
rect(0, 0, width, height-height/3);
}
y_2 = int(y_values[1])+height/2;
line(px_2, py_2, x_2, y_2);
py_2 = y_2;
px_2 = x_2;
x_2++;
}
}
void sendData() throws IOException {
msg = "<"+int(num_1)+","+int(num_2)+">";
mmOutputStream.write(msg.getBytes());
}
void findBluetooth() {
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
println("No bluetooth adapter available");
}
if (!mBluetoothAdapter.isEnabled()) {
Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
activity.startActivityForResult(enableBluetooth, 0);
}
Set pairedDevices = mBluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
print("Paired devices MAC Adress:");
printArray(pairedDevices);
for (BluetoothDevice device : pairedDevices) {
print("Paired devices by name:");
println(device.getName());
if (device.getName().equals(device_name)) {
mmDevice = device;
println("Bluetooth device name found");
break;
}
}
}
}
void connect() throws IOException {
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); //Standard SerialPortService ID
mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);
mmSocket.connect();
mmOutputStream = mmSocket.getOutputStream();
mmInputStream = mmSocket.getInputStream();
println("Bluetooth connected");
//final Handler handler = new Handler();
final byte delimiter = 33; //This is the ASCII code for a ! character
stop_thread = false;
buffer_index = 0;
readBuffer = new byte[1024];
runThread = new Thread(new Runnable() {
public void run() {
while (!Thread.currentThread().isInterrupted() && !stop_thread) {
try {
int bytesAvailable = mmInputStream.available();
if (bytesAvailable > 0) {
byte[] packetBytes = new byte[bytesAvailable];
mmInputStream.read(packetBytes);
for (int i = 0; i < bytesAvailable; i++) {
byte b = packetBytes[i];
if (b == delimiter) {
byte[] encodedBytes = new byte[buffer_index];
System.arraycopy(readBuffer, 0, encodedBytes, 0, encodedBytes.length);
final String data = new String(encodedBytes, "US-ASCII");
plot(data);
buffer_index = 0;
} else {
readBuffer[buffer_index++] = b;
}
}
}
}
catch (IOException ex)
{
stop_thread = true;
}
}
}
}
);
runThread.start();
}
void closeBluetooth() throws IOException {
stop_thread = true;
mmOutputStream.close();
mmInputStream.close();
mmSocket.close();
println("Bluetooth stopped");
}
class Permission {
PApplet parent;
boolean requestedPortraitImage = false;
Permission(PApplet pParent, String permissionName) {
parent = pParent;
parent.requestPermission("android.permission."+permissionName, "onPermissionResult", this);
}
void onPermissionResult(boolean granted) {
if (granted) println("User did grant permission.");
else println("User did NOT grant permission.");
}
}
void onPause() {
try {
closeBluetooth();
}
catch (Exception ex) {
}
super.onPause();
}
void onStop () {
try {
closeBluetooth();
}
catch (Exception ex) {
}
super.onStop();
}
void onRestart() {
try {
findBluetooth();
connect();
}
catch (IOException ex) {
println(ex);
}
}
```
and very thanks for you
and this is the arduino side
```auto
#include
#include
SoftwareSerial mySerial(11, 12); // RX, TX
unsigned long previous_millis;
boolean new_data = false;
float a = 0, b = 0;
float i_1 = 0, i_2 = 0;
int udi_1 = 20, udi_2 = 1;
int y_1 = 0, y_2 = 0;
const byte number_of_chars = 32;
char receivedChars[number_of_chars];
void setup() {
mySerial.begin(115200); // Set the baudrate equal to HC06 setting
Serial.begin(9600);
}
void loop() {
receivePacket();
if (new_data == true) {
parseData();
new_data = false;
}
while (mySerial.available() <= 0) {
y_1 = int(70 * sin(a));
a += i_1;
if (a > TWO_PI) a = 0;
mySerial.print(String(y_1) + '!');
y_2 = int(70 * sin(b));
b += i_2;
if (b > TWO_PI) b = 0;
mySerial.print(String(y_2) + '#');
}
}
void receivePacket() {
static boolean receiving = false;
static byte index = 0;
char start_mark = '<';
char end_mark = '>';
char rc;
while (mySerial.available() > 0 && new_data == false) {
rc = mySerial.read();
if (receiving == true) {
if (rc != end_mark) {
receivedChars[index] = rc;
index++;
if (index >= number_of_chars) {
index = number_of_chars - 1;
}
} else {
receivedChars[index] = '\0';
receiving = false;
index = 0;
new_data = true;
}
} else if (rc == start_mark) {
receiving = true;
}
}
}
void parseData() {
char * split;
split = strtok(receivedChars, ",");
udi_1 = atoi(split);
split = strtok(NULL, ",");
udi_2 = atoi(split);
i_1 = udi_1/100.0;
i_2 = udi_2/100.0;
Serial.println(i_1);
Serial.println(i_2);
}
```
---
### Author:  [@josephh](https://discourse.processing.org/u/josephh)
#### Post date: [February 6, 2021, 6:45pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/10 "2021-02-06T18:45:29Z")
Hi again,
When I said “working code”, I meant a simple example code that can be executed not your whole program.
> [@jafal](#):
>
> in this line how to add from int(num\_3) to int(num\_6)
I’m sorry but this is not clear at all 😉
Do you want to have this ??
```auto
"<" + int(num_1) + "," + int(num_2) + "," + int(num_3) + "," + int(num_4) + "," + int(num_5) + "," + int(num_6) + ">"
```
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [February 6, 2021, 7:10pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/11 "2021-02-06T19:10:23Z")
> [@josephh](#):
>
> When I said “working code”, I meant a simple example code that can be executed not your whole program.
its not the whole program. its the transmission just 😃 😃
yes this is what i want and i test it befor you send just now
```auto
"<" + int(num_1) + "," + int(num_2) + "," + int(num_3) + "," + int(num_4) + "," + int(num_5) + "," + int(num_6) + ">"
```
and i add t this
```auto
String msg = "<0,0,0,0,0,0>";
```
and in arduino
```auto
void parseData() {
char * split;
split = strtok(receivedChars, ",");
int_1 = atoi(split);
split = strtok(NULL, ",");
int_2 = atoi(split);
split = strtok(NULL, ",");
int_3 = atoi(split);
split = strtok(NULL, ",");
int_4 = atoi(split);
split = strtok(NULL, ",");
int_5 = atoi(split);
split = strtok(NULL, ",");
int_6= atoi(split);
```
thanks for you
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [February 6, 2021, 7:22pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/12 "2021-02-06T19:22:10Z")
> [@josephh](#):
>
> Also can you describe more precisely what is the goal of your program? (Because it’s difficult to understand with two sentences…) 😉
and harder if you saw the whole Package
❤ 😇 ❤
thanks for response
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [February 8, 2021, 3:27pm UTC](https://discourse.processing.org/t/unexpected-behavior-of-char-in-print-println/27609/13 "2021-02-08T15:27:52Z")
[josephh](https://discourse.processing.org/u/josephh)
hi
i did it
```auto
void sendData() throws IOException {
msg2="<"+ int(val1)+","+int(val2)+","+int(val3)+","+int(val4)+","+int(val5)+int(val6)+">";
mmOutputStream.write(msg2.getBytes());
}
```
arduino
```auto
void parseData() {
char * split;
split = strtok(receivedChars, ",");
int_1 = atoi(split);
split = strtok(NULL, ",");
int_2 = atoi(split);
split = strtok(NULL, ",");
int_3 = atoi(split);
split = strtok(NULL, ",");
int_4 = atoi(split);
split = strtok(NULL, ",");
int_5= atoi(split);
Serial.println( int_1);
Serial.println(int_2);
//Serial.println(int_3);
//Serial.println(int_4);
//Serial.println(int_5);
}
```