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Java toString方法不显示,但编译代码_Java_Oop_Tostring - Fatal编程技术网

Java toString方法不显示,但编译代码

Java toString方法不显示,但编译代码,java,oop,tostring,Java,Oop,Tostring,Java代码已编译,但不显示toString方法。我需要在子类中调用它吗?或者toString是否有不同的方式来显示实例变量 public class Animal { //instance variables private int numberOfLegs; private boolean sleep; //Default Constructor public Animal() { numberOfLegs = 6;

Java代码已编译,但不显示toString方法。我需要在子类中调用它吗?或者toString是否有不同的方式来显示实例变量

public class Animal { 
    //instance variables
    private int numberOfLegs; 
    private boolean sleep; 

    //Default Constructor
    public Animal() {
        numberOfLegs = 6;
        sleep = true;
    }

    // Constructor
    public Animal(int numberOfLegs, boolean sleep){
        this.numberOfLegs = numberOfLegs;
        this.sleep = sleep;
    }

    //toString method
    public String toString (int numberOfLegs, boolean sleep){
        return numberOfLegs + " legs, sleep: " + sleep;
    }
    //walk method
    void walk(){
        System.out.print("walking ");
    }
    public static void main(String[] args) {
        Animal animal1 = new Tiger();
        animal1.walk();
        animal1.toString(4, false);
    } //end main
}// end animalclass

class Tiger extends Animal {
    void walk(){
        super.walk();
        System.out.println("a Tiger");
    }
    public Tiger(){
        super();
    }
} //end Tiger class
toString()
返回
字符串。它不执行任何显示逻辑(不同于
walk()
方法,该方法打印内容但不返回任何内容)

您需要使用
System.out.println()或其他方式显示它

toString()
方法也不应接受参数。你已经知道动物有多少条腿了,所以这些参数是无用的