一个错误的程序，不知道问题出在哪里？？
public class People{
public static void main(String[] args){
double height;
int age;
int sex;
void cry(){
System.out.println("i am crying!");
}
void laugh(){
System.out.println("i am laughing!");
}
void printBaseMes(){
System.out.println("my height is"+height+"cm");
System.out.println("my age is"+age+"old");
if(this.sex ==0)
System.out.println("I am male!");
else
System.out.println("I am female!");
}
cry();
laugh();
printBaseMes();
}
}
