米换英寸 运行结果均为0

要求是将米换算为码.英尺.英寸（yard，foot，inch）

代码并没有对，全局变量进行赋值，且你的换算代码是有问题的;

    Integer meters;
    Double yard;
    Double foot;
    Double inch;
    
    public void convert() {
        meters = 8;
        this.meters = meters;
        //1米等于1.09码
        this.yard = meters * 1.09;
        //1米等于39.37008英寸
        this.inch = meters * 39.37008;
        //1米等于3.28英尺
        this.foot = meters * 3.28;
        print();
    }

    void print() {
        System.out.println(meters + " metres in yards,feet and inches is:"
                + yard + " yards," + foot + " feet and" + inch + " inches.");
    }