💖 单选题
💖 填空题
💖 判断题
💖 程序阅读题
1. 读代码写结果
class A
{
int m = 5;
void zengA(int x)
{
m = m + x;
}
int jianA(int y)
{
return m - y;
}
}
class B extends A
{
int m = 3;
int jianA(int z)
{
return super.jianA(z) + m;
}
}
public class Test
{
public static void main(String[] args)
{
A a1 = new A();
A a2 = new A();
B b = new B();
A t = (A) b;
A a3, a4;
a3 = b;
a4 = a1;
a1.zengA(5);
a3.zengA(6);
b.m = 4;
System.out.println(a1.m); // 【代码 1】
System.out.println(a2.m); // 【代码 2】
System.out.println(a3.m); // 【代码 3】
System.out.println(a4.m); // 【代码 4】
System.out.println(a3.jianA(1)); // 【代码 5】11-1+4 = 14
}
}
2. 读代码写结果
abstract class A
{
public abstract double f(double x, double y);
}
class B extends A
{
double m;
public double f(double a, double b)
{
return a * b + m;
}
}
public class E
{
public static void main(String args[])
{
B b = new B();
A a = b;
b.m = 2.0;
System.out.println(a.f(2.0, 3.0)); // 【代码 1】 2 * 3 + 2 = 8.0
}
}
3. 读代码写结果
class A
{
static int m = 5;
void zengA(int x)
{
m = m + x;
}
}
public class E
{
public static void main(String args[])
{
A a1 = new A();
A a2 = new A();
a2.zengA(5);
System.out.println(a1.m); // 【代码 1】
System.out.println(a2.m); // 【代码 2】
}
}
4. 读代码写结果
class A
{
int x = 100;
double y = 200.3;
A(int x)
{
x = x;
}
A(double y)
{
this.y = y;
}
double B()
{
return x + y;
}
}
public class Test
{
public static void main(String[] args)
{
A a1 = new A(-80);// 构造方法:细节 x=x,相当于啥也没干
System.out.println(a1.B()); // 【代码 1】100+200.3 = 300.3
A a2 = new A(60.5);
System.out.println(a2.B()); // 【代码 2】
}
}
5. 读代码写结果
interface A
{
public double f(double x, double y);
}
class B implements A
{
double m;
public double f(double a, double b)
{
return a * b + m;
}
}
public class E
{
public static void main(String args[])
{
B b = new B();
A a = b;
b.m = 2.0;
System.out.println(a.f(2.0, 3.0));// 2 * 3 + 2 = 8
}
}