This example is for Processing 3+. If you have a previous version, use the examples included with your software. If you see any errors or have suggestions, please let us know.

Characters Strings.

The character datatype, abbreviated as char, stores letters and symbols in the Unicode format, a coding system developed to support a variety of world languages. Characters are distinguished from other symbols by putting them between single quotes ('P').

A string is a sequence of characters. A string is noted by surrounding a group of letters with double quotes ("Processing"). Chars and strings are most often used with the keyboard methods, to display text to the screen, and to load images or files.

The String datatype must be capitalized because it is a complex datatype. A String is actually a class with its own methods, some of which are featured below.

char letter;
String words = "Begin...";

void setup() {
  size(640, 360);
  // Create the font
  textFont(createFont("SourceCodePro-Regular.ttf", 36));

void draw() {
  background(0); // Set background to black

  // Draw the letter to the center of the screen
  text("Click on the program, then type to add to the String", 50, 50);
  text("Current key: " + letter, 50, 70);
  text("The String is " + words.length() +  " characters long", 50, 90);
  text(words, 50, 120, 540, 300);

void keyTyped() {
  // The variable "key" always contains the value 
  // of the most recent key pressed.
  if ((key >= 'A' && key <= 'z') || key == ' ') {
    letter = key;
    words = words + key;
    // Write the letter to the console