//method that return String
public String method()
{
    //must return value of String type
    return new String( "..." );
}

//method that return int
public int method()
{
    //must return value of int type
    return digital;
}

//if here does not need to return any value
//then you can choose "void", means do not 
//need to "return"
public void method()
{
    //no word "return"
}

------解决方案--------------------
不需要返回值的方法的情况

------解决方案--------------------
void 不返回值 好像基础书上都有说吧