Notes

import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

/**
* Write a description of class Human here.
*
* @author (your name)
* @version (a version number or a date)
*/
public class Human extends Actor
{
final int Gravity = 1;
int Velocity;
/**
* Act - do whatever the Human wants to do. This method is called whenever
* the 'Act' or 'Run' button gets pressed in the environment.
*/
public void act()
{
// Add your action code here.
fall();
move();
if(Greenfoot.isKeyDown("up") && isOnObj()){
jump();
}
if(Greenfoot.isKeyDown("space")){
jump();
}
}
public void fall(){
setLocation(getX(),getY()+Velocity);
if(isOnObj()) Velocity = 0;
else Velocity += Gravity;

}
public void jump(){
Velocity = -20;
}
public void move(){
int x = getX();
int y = getY();
if(Greenfoot.isKeyDown("right")){
x = x + 5;
}

if(Greenfoot.isKeyDown("left")){
x = x - 5;
}
setLocation(x,y);
}
public boolean isOnObj(){
boolean onObj = false;
if(getY() > getWorld().getHeight() -45)onObj = true;
int imgWidth = getImage().getWidth();
int imgHeight = getImage().getHeight();

if(getOneObjectAtOffset(imgWidth / 2, imgHeight / 2, Croc.class) != null
|| getOneObjectAtOffset(imgWidth / -2, imgHeight / -2, Croc.class) != null) {
onObj = true;

}

return onObj;
}
}