Question

JAVA将一个类里面的值传到另一个类

有 A B C三个类
public class A {
int a = 5;
}
public class B {
int b;
将 a的值传给b
//分别用构造和方法传递来做.
}
C类打印出 b的值为5;

Answer 1

你好，按照你的要求代码如下

class A {
int a = 5;
}

class B {
int b;

public B() {}

public B(int b) {
this.b = b;
}

public void setB(int b) {
this.b = b;
}
}

class C {
public static void main(String[] args) {
A a = new A();
B b = new B(a.a);// 用构造传递
b.setB(a.a);// 用方法传递
}
}

Answer 2

构造器：
class A{
int a = 5;
}
class B{
int b;
B(int a){
b=a;
}
}
public class C{
public static void main(String[] args) {
A aa = new A();
B bb = new B(aa.a);
System.out.println(bb.b);
}
}
方法传递：
class A{
int a = 5;
}
class B{
int b;
public int getB() {
return b;
}
public void setB(int b) {
this.b = b;
}
}
public class C{
public static void main(String[] args) {
A aa = new A();
B bb = new B();
bb.setB(aa.a);
System.out.println(bb.getB());
}
}