*New Coder: How do I make my character jump up and then come back down

Jmartinez21

Hello my name is Jorge and I am new to coding, I have been working on this code for about 3 months and this code is for my Final Project.
I already got my character to move left and right. Can someone please help me on how to make my character jump. Thank You.

Grass a;
Guy b;
Dirt c;
Cloud d;
Red_Spike e;

void setup() {
  size(800,400);
  a = new Grass();
  b = new Guy();
  c = new Dirt();
  d = new Cloud();
  e = new Red_Spike();
}
void draw() {
  background(#1DB4ED);
  line(0,300,3000,300);
  a.display();
  b.display();
  c.display();
  d.display();
  e.display();
  fill(#FF0808); 
  textSize(50);
  text("Red Spikes", 280, 150); 
}

class Grass {

  void display(){
  fill(#09B212);
  rect(0,300,20,20);
  rect(20,300,20,20);
  rect(40,300,20,20);
  rect(60,300,20,20);
  rect(80,300,20,20);
  rect(100,300,20,20);
  rect(120,300,20,20);
  rect(140,300,20,20);
  rect(160,300,20,20);
  rect(180,300,20,20);
  rect(200,300,20,20);
  rect(220,300,20,20);
  rect(240,300,20,20);
  rect(260,300,20,20);
  rect(280,300,20,20);
  rect(300,300,20,20);
  rect(320,300,20,20);
  rect(340,300,20,20);
  rect(360,300,20,20);
  rect(380,300,20,20);
  rect(400,300,20,20);
  rect(420,300,20,20);
  rect(440,300,20,20);
  rect(460,300,20,20);
  rect(480,300,20,20);
  rect(500,300,20,20);
  rect(520,300,20,20);
  rect(540,300,20,20);
  rect(560,300,20,20);
  rect(580,300,20,20);
  rect(600,300,20,20);
  rect(620,300,20,20);
  rect(640,300,20,20);
  rect(660,300,20,20);
  rect(680,300,20,20);
  rect(700,300,20,20);
  rect(720,300,20,20);
  rect(740,300,20,20);
  rect(760,300,20,20);
  rect(780,300,20,20);
  rect(800,300,20,20);
  rect(820,300,20,20);
  rect(840,300,20,20);
   rect(860,300,20,20);
   rect(880,300,20,20);
   rect(900,300,20,20);
   rect(920,300,20,20);
   rect(940,300,20,20);
   rect(960,300,20,20);
   rect(980,300,20,20);
   rect(1000,300,20,20);
   rect(1020,300,20,20);
   rect(1040,300,20,20);
     rect(1060,300,20,20);
     rect(1080,300,20,20);
     rect(1100,300,20,20);
     rect(1120,300,20,20);
     rect(1140,300,20,20);
     rect(1160,300,20,20);
     rect(1180,300,20,20);
     rect(1200,300,20,20);
     rect(1220,300,20,20);
     rect(1240,300,20,20);
     rect(1260,300,20,20);
     rect(1280,300,20,20);
     rect(1300,300,20,20);
     rect(1320,300,20,20);
     rect(1340,300,20,20);
     rect(1360,300,20,20);
     rect(1380,300,20,20);
     rect(1400,300,20,20);
     rect(1420,300,20,20);
     rect(1440,300,20,20);
     rect(1460,300,20,20);
     rect(1480,300,20,20);
     rect(1500,300,20,20);
     rect(1520,300,20,20);
     rect(1540,300,20,20);
     rect(1560,300,20,20);
     rect(1580,300,20,20);
     rect(1600,300,20,20);
     rect(1620,300,20,20);
     rect(1640,300,20,20);
     rect(1660,300,20,20);
     rect(1680,300,20,20);
     rect(1700,300,20,20);
     rect(1720,300,20,20);
     rect(1740,300,20,20);
     rect(1760,300,20,20);
     rect(1780,300,20,20);
     rect(1800,300,20,20);
     rect(1820,300,20,20);
     rect(1840,300,20,20);
     rect(1860,300,20,20);
     rect(1880,300,20,20);
     rect(1900,300,20,20);
  }
}


class Dirt {

void display() {
    fill(165,42,42);
    rect(0,320,100,80);
    rect(100,320,100,80);
    rect(200,320,100,80);
    rect(300,320,100,80);
    rect(400,320,100,80);
    rect(500,320,100,80);
    rect(600,320,100,80);
    rect(700,320,100,80);
    rect(800,320,100,80);
    rect(900,320,100,80);
    rect(1000,320,100,80);
    rect(1100,320,100,80);
    rect(1200,320,100,80);
    rect(1300,320,100,80);
    rect(1400,320,100,80);
    rect(1500,320,100,80);
    rect(1600,320,100,80);
    rect(1700,320,100,80);
    rect(1800,320,100,80);
    rect(1900,320,100,80);
    rect(2000,320,100,80);
    rect(2100,320,100,80);
    rect(2200,320,100,80);
    rect(2300,320,100,80);
    rect(2400,320,100,80);
    rect(2500,320,100,80);
    rect(2600,320,100,80);
    rect(2700,320,100,80);
    rect(2800,320,100,80);
    rect(2900,320,100,80);
    rect(3000,320,100,80);
    rect(3100,320,100,80);
    rect(3200,320,100,80);
    rect(3300,320,100,80);
    rect(3400,320,100,80);
    rect(3500,320,100,80);
    rect(3600,320,100,80);
    rect(3700,320,100,80);
    rect(3800,320,100,80);
    rect(3900,320,100,80);
    rect(4000,320,100,80);
    rect(4100,320,100,80);
    rect(4200,320,100,80);
    rect(4300,320,100,80);
    rect(4400,320,100,80);
    rect(4500,320,100,80);
    rect(4600,320,100,80);
    rect(4700,320,100,80);
    rect(4800,320,100,80);
    rect(4900,320,100,80);
    rect(5000,320,100,80);
    rect(5100,320,100,80);
    rect(5200,320,100,80);
    rect(5300,320,100,80);
    rect(5400,320,100,80);
    rect(5500,320,100,80);
  }
}

class Cloud {

  void display() {
    pushMatrix();
    translate(30, 20);
    fill(255);
    ellipse(60,65,40,40); 
    ellipse(130,65,40,40); 
    ellipse(80,80,40,40); 
    ellipse(80,50,40,40); 
    ellipse(110,80,40,40);
    ellipse(110,50,40,40);
    popMatrix();
    pushMatrix();
    translate(570, 70);
    ellipse(60,65,40,40); 
    ellipse(130,65,40,40); 
    ellipse(80,80,40,40); 
    ellipse(80,50,40,40); 
    ellipse(110,80,40,40);
    ellipse(110,50,40,40);
    popMatrix();
  }
}

  class Red_Spike {

  void display() {
    pushMatrix();
    translate(140,25);
    fill(#FF0808);
    triangle(230,275,258,220,286,275);
    popMatrix();
    pushMatrix();
    translate(572,255);
    triangle(30, 45, 38, 30, 46, 45);
    popMatrix();
    pushMatrix();
    translate(592,255);
    triangle(30, 45, 38, 30, 46, 45);
    popMatrix();
    pushMatrix();
    translate(692,255);
    triangle(30, 45, 38, 30, 46, 45);
    popMatrix();
    pushMatrix();
    translate(712,255);
    triangle(30, 45, 38, 30, 46, 45);
    popMatrix();
  }
}

class Guy {

  void display(){
  fill(255);
  strokeWeight(2);
  ellipse(x,j,10,10);
 line(x,y,x,f);
  line(x,y,i,z);
  line(x,y,h,z);
  line(x,f,i,g);
  line(x,f,h,g);

  }
}

void keyPressed(){
  if ((key == CODED) && (keyCode == RIGHT)){
    x=x+6;
    y=y;
   f=f;
    i=i+6;
 //  z=z+6;
    h=h+6;
  //  j=j+6;
    g=g;
  }
  if ((key == CODED) && (keyCode == LEFT)){
    x=x-6;
     y=y;
   f=f;
    i=i-6;
 // z=z-6;
    h=h-6;
 //   j=j-6;
    g=g;
  }
  if ((key == CODED) && (keyCode == UP)){

  }
}

KevinWorkman

Shameless self-promotion: I wrote a tutorial on collision detection, which includes a section on collision detection between the player and the ground when jumping, available here. Check out the Snapping to an Edge section.