简单java类比较
class Che{ private String name; private double price; public Che(){} public Che(String name,double price){ this.name = name; this.price = price; } public String getName(){ return name; } public void setName(){ this.name = name; } public double getPrice(){ return price; } public void setPrice(double price){ this.price = price; } public String getInfo(){ return "车名:"+name+"价格:"+price; } public boolean compare(Che che){ if(che==null){ return false;} if(che==this){ return true;} if(this.getName().equals(che.getName()) && this.getPrice()==che.getPrice()){ return true; } return false; } } class Statt { public static void main(String[] args) { Che c1 = new Che("大众",100000.0); Che c2 = new Che("大众",100000.0); Che c3 = new Che("奔驰",2000000.0); //System.out.println(c1==c2); //System.out.println(c2==c3); //if(c1.getName().equals(c2.getName()) && c1.getPrice()==c2.getPrice()){ // System.out.println("c1和c2相等"); //}else{ // System.out.println("错误"); //} System.out.println(c1.compare(c2)); System.out.println(c1.compare(c3)); System.out.println(c1==null); System.out.println(c1==c1); } }