1、使用键盘来改变输出的图形输入代码：void setup() {size(240, 120);smooth();}void draw() {background(204);line(20, 20, 220, 100);if (keyPressed) {//如果按下按键，显示直线line(220, 20, 20, 100);}}
2、输出效果：当按下键盘任意按键时，窗口会变成两条直线；如果没有按键按下，窗口中只会显示一条直线。
3、显示按下的按键输入代码：void setup() {size(120, 120);textSize(64);textAlign(CENTER);}void draw() {background(0);text(key, 60, 80);}
4、输出结果：当有按键按下时，窗口会显示出按下的相应按键
5、Processing 识别不同的字符输入代码：void setup猾诮沓靥() {size(120, 120);smooth();}void draw() {background(204像粜杵泳);if (keyPressed) {if ((key == 'h') || (key == 'H')) {line(30, 60, 90, 60);}if ((key == 'n') || (key == 'N')) {line(30, 20, 90, 100);}}line(30, 20, 30, 100);line(90, 20, 90, 100);}输出效果如下图所示当没有按键按下时，输出为两条竖线当按下 n 或 N 时，输出为 N当按下 h 或 H 时，输出为 H
6、通过方向键，移动显示的图形输入代码：int x = 215;void setup() {size(480, 120);}void draw() {if (keyPressed && (key == CODED)) { // If it’s a coded keyif (keyCode == LEFT) { // If it’s the left arrowx--;} else if (keyCode == RIGHT) { // If it’s the right arrowx++;}}rect(x, 45, 50, 50);}输出效果为当按下方向键的左键和右键时，窗口中显示的图形会向相应的方向移动
7、图形跟随鼠标运动，并且在单击左键时，图形改变图形的尺寸输入代码：float x = 60;float y = 440;int r锾攒揉敫adius = 45;int bodyHeight = 160;int neckHeight = 70;float easing = 0.02;void setup() {size(360, 480);smooth();strokeWeight(2);ellipseMode(RADIUS);}void draw() {int targetX = mouseX;x += (targetX - x) * easing;if (mousePressed) {neckHeight = 16;bodyHeight = 90;} else {neckHeight = 70;bodyHeight = 160;}float ny = y - bodyHeight - neckHeight - radius;background(204);stroke(102);line(x+12, y-bodyHeight, x+12, ny);line(x+12, ny, x-18, ny-43);line(x+12, ny, x+42, ny-99);line(x+12, ny, x+78, ny+15);noStroke();fill(102);ellipse(x, y-33, 33, 33);fill(0);rect(x-45, y-bodyHeight, 90, bodyHeight-33);fill(0);ellipse(x+12, ny, radius, radius);fill(255);ellipse(x+24, ny-6, 14, 14);fill(0);ellipse(x+24, ny-6, 3, 3);}
